To provide an end effector.

An end effector 16 for use with a surgical apparatus, includes: a staple cartridge 32 having a tissue contact surface specifying a center-longitudinal-direction slot; an anvil plate 302 having a tissue contact surface specifying a center-longitudinal-direction slot; and a folded surgical buttress 500a. The folded surgical buttress is overlapped with each of the tissue contact surfaces of the staple cartridge and the anvil plate. The folded surgical buttress is held on the tissue contact surfaces of the staple cartridge and the anvil plate. The surgical buttress specifies a bottom surface, and includes a proximal part having a proximal edge, and a distal part having a distal edge. At least one of the proximal and distal parts is folded with respect to the bottom surface.