diff --git a/crates/verifier/src/ctx.rs b/crates/verifier/src/ctx.rs
new file mode 100644
index 00000000..4a0441dd
--- /dev/null
+++ b/crates/verifier/src/ctx.rs
@@ -0,0 +1,39 @@
+//! Verification context
+
+use sonatina_ir::{module::FuncRef, ControlFlowGraph, Function};
+
+use crate::{
+    error::{ErrorData, ErrorKind, TraceInfo},
+    ErrorStack,
+};
+
+pub struct VerificationCtx<'a> {
+    pub func_ref: FuncRef,
+    pub func: &'a Function,
+    pub cfg: ControlFlowGraph,
+    pub error_stack: ErrorStack,
+}
+
+impl<'a> VerificationCtx<'a> {
+    pub fn new(func_ref: FuncRef, func: &'a Function) -> Self {
+        let mut cfg = ControlFlowGraph::new();
+        cfg.compute(func);
+
+        Self {
+            func_ref,
+            func,
+            cfg,
+            error_stack: ErrorStack::default(),
+        }
+    }
+
+    pub fn report_nonfatal(&mut self, errs: &[ErrorData]) {
+        for e in errs {
+            let _err_ref = self.error_stack.push(*e);
+        }
+    }
+
+    pub fn report_fatal(&mut self, kind: ErrorKind, trace_info: TraceInfo) {
+        self.error_stack.fatal_error = Some(ErrorData::new(kind, trace_info));
+    }
+}
diff --git a/crates/verifier/src/error_stack.rs b/crates/verifier/src/error_stack.rs
index 6f6ec236..08b0e749 100644
--- a/crates/verifier/src/error_stack.rs
+++ b/crates/verifier/src/error_stack.rs
@@ -5,12 +5,13 @@ use crate::error::{Error, ErrorData, ErrorRef};
 
 #[derive(Debug, Default)]
 pub struct ErrorStack {
-    pub errors: PrimaryMap<ErrorRef, ErrorData>,
+    pub fatal_error: Option<ErrorData>,
+    pub non_fatal_errors: PrimaryMap<ErrorRef, ErrorData>,
 }
 
 impl ErrorStack {
     pub fn push(&mut self, err: ErrorData) -> ErrorRef {
-        self.errors.push(err)
+        self.non_fatal_errors.push(err)
     }
 
     pub fn into_errs_iter(
@@ -18,8 +19,16 @@ impl ErrorStack {
         func: &Function,
         func_ref: FuncRef,
     ) -> impl IntoIterator<Item = Error<'_>> {
-        self.errors
-            .into_iter()
+        let Self {
+            fatal_error,
+            non_fatal_errors: mut errs,
+        } = self;
+
+        if let Some(err) = fatal_error {
+            errs.push(err);
+        }
+
+        errs.into_iter()
             .map(move |(_, err)| Error::new(err, func, func_ref))
     }
 }
diff --git a/crates/verifier/src/lib.rs b/crates/verifier/src/lib.rs
index d32fd422..0fe1e587 100644
--- a/crates/verifier/src/lib.rs
+++ b/crates/verifier/src/lib.rs
@@ -1,2 +1,9 @@
+pub mod ctx;
 pub mod error;
 pub mod error_stack;
+pub mod pass;
+pub mod passes;
+
+pub use ctx::VerificationCtx;
+pub use error_stack::ErrorStack;
+pub use pass::VerificationPass;
diff --git a/crates/verifier/src/pass.rs b/crates/verifier/src/pass.rs
new file mode 100644
index 00000000..24270ba1
--- /dev/null
+++ b/crates/verifier/src/pass.rs
@@ -0,0 +1,14 @@
+//! Verification pass
+
+use crate::VerificationCtx;
+
+pub trait VerificationPass {
+    fn run(&mut self, ctx: &mut VerificationCtx) -> VerificationResult;
+}
+
+#[derive(Debug, PartialEq, Eq)]
+pub enum VerificationResult {
+    Pass,
+    Fail,
+    FailFatal,
+}
diff --git a/crates/verifier/src/passes/block/end_in_terminator.rs b/crates/verifier/src/passes/block/end_in_terminator.rs
new file mode 100644
index 00000000..4df5ff9a
--- /dev/null
+++ b/crates/verifier/src/passes/block/end_in_terminator.rs
@@ -0,0 +1,137 @@
+use crate::{
+    error::{
+        ErrorKind::{NotEndedByTerminator, TerminatorBeforeEnd},
+        TraceInfoBuilder,
+    },
+    pass::VerificationResult,
+    VerificationCtx, VerificationPass,
+};
+
+pub struct EndInTerminator;
+
+impl VerificationPass for EndInTerminator {
+    fn run(&mut self, ctx: &mut VerificationCtx) -> VerificationResult {
+        let layout = &ctx.func.layout;
+        let dfg = &ctx.func.dfg;
+
+        for block in layout.iter_block() {
+            let last_inst = layout.last_inst_of(block).expect("pass dependency error");
+
+            // check last instruction in block is terminator
+            if !dfg.is_terminator(last_inst) {
+                let trace_info = TraceInfoBuilder::new(ctx.func_ref).block(block).build();
+                ctx.report_fatal(NotEndedByTerminator(last_inst), trace_info);
+
+                return VerificationResult::FailFatal;
+            }
+
+            // check no instruction mid-block is terminator
+            for inst in layout.iter_inst(block) {
+                if inst == last_inst {
+                    break;
+                }
+
+                if dfg.is_terminator(inst) {
+                    let trace_info = TraceInfoBuilder::new(ctx.func_ref).block(block).build();
+                    ctx.report_fatal(TerminatorBeforeEnd(inst), trace_info);
+
+                    return VerificationResult::FailFatal;
+                }
+            }
+        }
+
+        VerificationResult::Pass
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use sonatina_ir::{
+        builder::test_util::test_func_builder,
+        inst::{
+            control_flow::{Jump, Return},
+            logic::Xor,
+        },
+        isa::Isa,
+        Type,
+    };
+
+    use super::*;
+
+    #[test]
+    fn last_inst_not_terminator() {
+        let (evm, mut builder) = test_func_builder(&[Type::I1], Type::Unit);
+        let is = evm.inst_set();
+
+        let b0 = builder.append_block();
+
+        let arg = builder.args()[0];
+
+        builder.switch_to_block(b0);
+        let c1 = builder.make_imm_value(false);
+        builder.insert_inst_with(|| Xor::new(is, arg, c1), Type::I1);
+
+        builder.seal_all();
+
+        let module = builder.finish().build();
+        let func_ref = module.iter_functions().next().unwrap();
+        let func = &module.funcs[func_ref];
+
+        let mut ctx = VerificationCtx::new(func_ref, func);
+        let res = EndInTerminator.run(&mut ctx);
+        assert_eq!(res, VerificationResult::FailFatal);
+
+        let errs = ctx
+            .error_stack
+            .into_errs_iter(func, func_ref)
+            .into_iter()
+            .collect::<Vec<_>>();
+        assert_eq!(1, errs.len());
+
+        assert_eq!(
+            "last instruction not terminator, xor v0 0.i1
+trace_info:
+0: block0
+1: func public %test_func(i1) -> unit",
+            errs[0].to_string()
+        );
+    }
+
+    #[test]
+    fn terminator_mid_block() {
+        let (evm, mut builder) = test_func_builder(&[], Type::Unit);
+        let is = evm.inst_set();
+
+        let b0 = builder.append_block();
+        let b1 = builder.append_block();
+
+        builder.switch_to_block(b0);
+        builder.insert_inst_no_result(Jump::new(is, b1));
+        builder.insert_inst_no_result_with(|| Return::new(is, None));
+
+        builder.seal_all();
+
+        let module = builder.finish().build();
+        let func_ref = module.iter_functions().next().unwrap();
+        let func = &module.funcs[func_ref];
+
+        let mut ctx = VerificationCtx::new(func_ref, func);
+        let res = EndInTerminator.run(&mut ctx);
+        assert_eq!(res, VerificationResult::FailFatal);
+
+        let errs = ctx
+            .error_stack
+            .into_errs_iter(func, func_ref)
+            .into_iter()
+            .collect::<Vec<_>>();
+        assert_eq!(1, errs.len());
+
+        assert_eq!(
+            "terminator instruction mid-block, jump block1
+trace_info:
+0: block0
+1: func public %test_func() -> unit",
+            errs[0].to_string()
+        );
+    }
+}
diff --git a/crates/verifier/src/passes/block/mod.rs b/crates/verifier/src/passes/block/mod.rs
new file mode 100644
index 00000000..510dfdc9
--- /dev/null
+++ b/crates/verifier/src/passes/block/mod.rs
@@ -0,0 +1,5 @@
+//! Passes to verify block integrity
+
+pub mod end_in_terminator;
+
+pub use end_in_terminator::EndInTerminator;
diff --git a/crates/verifier/src/passes/mod.rs b/crates/verifier/src/passes/mod.rs
new file mode 100644
index 00000000..a863eaad
--- /dev/null
+++ b/crates/verifier/src/passes/mod.rs
@@ -0,0 +1 @@
+pub mod block;