diff --git a/compile.c b/compile.c
index fc6453a..4bc68c5 100644
--- a/compile.c
+++ b/compile.c
@@ -1872,6 +1872,7 @@ iseq_specialized_instruction(rb_iseq_t *iseq, INSN *iobj)
 		switch (mid) {
 		  case idLength: SP_INSN(length); break;
 		  case idSize:	 SP_INSN(size);	  break;
+		  case idEmpty:  SP_INSN(empty);  break;
 		  case idSucc:	 SP_INSN(succ);	  break;
 		  case idNot:	 SP_INSN(not);	  break;
 		}
diff --git a/id.c b/id.c
index e5f971d..59961c5 100644
--- a/id.c
+++ b/id.c
@@ -41,6 +41,7 @@ Init_id(void)
     REGISTER_SYMID(idEach, "each");
     REGISTER_SYMID(idLength, "length");
     REGISTER_SYMID(idSize, "size");
+    REGISTER_SYMID(idEmpty, "empty?");
     REGISTER_SYMID(idLambda, "lambda");
     REGISTER_SYMID(idIntern, "intern");
     REGISTER_SYMID(idGets, "gets");
diff --git a/insns.def b/insns.def
index e55ec30..6264333 100644
--- a/insns.def
+++ b/insns.def
@@ -1991,6 +1991,44 @@ opt_size
 
 /**
   @c optimize
+  @e optimized empty?
+  @j 最適化された recv.empty?()。
+ */
+DEFINE_INSN
+opt_empty
+(IC ic)
+(VALUE recv)
+(VALUE val)
+{
+    if (!SPECIAL_CONST_P(recv)) {
+	if (HEAP_CLASS_OF(recv) == rb_cString &&
+	    BASIC_OP_UNREDEFINED_P(BOP_EMPTY, STRING_REDEFINED_OP_FLAG)) {
+	    if (RSTRING_LEN(recv) == 0) val = Qtrue;
+	    else val = Qfalse;
+	}
+	else if (HEAP_CLASS_OF(recv) == rb_cArray &&
+		 BASIC_OP_UNREDEFINED_P(BOP_EMPTY, ARRAY_REDEFINED_OP_FLAG)) {
+	    if (RARRAY_LEN(recv) == 0) val = Qtrue;
+	    else val = Qfalse;
+	}
+	else if (HEAP_CLASS_OF(recv) == rb_cHash &&
+		 BASIC_OP_UNREDEFINED_P(BOP_EMPTY, HASH_REDEFINED_OP_FLAG)) {
+	    if (RHASH_EMPTY_P(recv)) val = Qtrue;
+	    else val = Qfalse;
+	}
+	else {
+	    goto INSN_LABEL(normal_dispatch);
+	}
+    }
+    else {
+      INSN_LABEL(normal_dispatch):
+	PUSH(recv);
+	CALL_SIMPLE_METHOD(0, idEmpty, recv);
+    }
+}
+
+/**
+  @c optimize
   @e optimized succ
   @j 最適化された recv.succ()。
  */
diff --git a/template/id.h.tmpl b/template/id.h.tmpl
index 0e54e76..7896d8b 100644
--- a/template/id.h.tmpl
+++ b/template/id.h.tmpl
@@ -20,6 +20,7 @@ method_ids = %w[
   MethodMissing
   Length
   Size
+  Empty
   Gets
   Succ
   Each
diff --git a/vm_insnhelper.h b/vm_insnhelper.h
index 4d5f0e3..40cd88b 100644
--- a/vm_insnhelper.h
+++ b/vm_insnhelper.h
@@ -49,6 +49,7 @@ enum {
   BOP_ASET,
   BOP_LENGTH,
   BOP_SIZE,
+  BOP_EMPTY,
   BOP_SUCC,
   BOP_GT,
   BOP_GE,