This stent delivery system includes: a guide catheter inserted inside a stent, and inserted into the interior of the living body with the stent by a guide member inserted inside the guide catheter; a guide member inserted inside the guide catheter, and which guides the guide catheter and the stent to the interior of a living body; a pusher catheter inserted into the interior of the living body with the guide catheter in a state where the guide catheter is inserted inside the pusher catheter, and which pushes the stent along the guide catheter; and an engaging portion disposed on a head section of the guide catheter protruding from the stent, which engages with the stent in a state where the guide member is inserted into the head section, and which releases the stent in a state where the guide member is retracted away from the head section.