A stent delivery device (10) according to the present invention includes a stent (12) arranged in a self-expandable state between a shaft (14) and an inner sheath (18). In a state where an outer sheath (16) is moved rearward and an expansion limiting portion (34) is exposed outward, the expansion limiting portion (34) formed in a distal portion of the inner sheath (18) limits expansion of the stent (12) so that an outer diameter of a distal end of the stent (12) becomes a first diameter (D1) which is larger than an inner diameter (Da) of the outer sheath (16), and in a state where the inner sheath (18) is moved rearward and the stent (12) is exposed outward, the stent (12) expands so that the outer diameter of the distal end of the stent (12) becomes a second diameter (D2) which is larger than the first diameter (D1).
