A stent delivery device is disclosed, which includes a stent arranged in a self-expandable state between a shaft and an inner sheath. In a state where an outer sheath is moved rearward and an expansion limiting portion is exposed outward, the expansion limiting portion formed in a distal portion of the inner sheath limits expansion of the stent so that an outer diameter of a distal end of the stent becomes a first diameter (D1) which is larger than an inner diameter (Da) of the outer sheath, and in a state where the inner sheath is moved rearward and the stent is exposed outward, the stent expands so that the outer diameter of the distal end of the stent becomes a second diameter (D2) which is larger than the first diameter (D1).
