This shock absorber includes a piston main body and a piston band. The piston main body has, at an outer peripheral portion thereof, a stepped portion including a large-diameter surface portion, a stepped surface portion and a small-diameter surface portion. The piston band has, at an outer peripheral portion thereof, a large diameter portion, a medium diameter portion formed so as to have a smaller diameter than the large diameter portion, and a small diameter portion formed between the large diameter portion and the medium diameter portion so as to have a smaller diameter than the medium diameter portion, in a state before being disposed in a cylinder. At one end on the side close to a tip portion of a piston rod, an inner peripheral surface is inclined toward the piston main body side from the large-diameter surface portion to a small-diameter surface portion of the stepped portion.