A cap installable on a distal end portion of an endoscope according to the present invention has: a cap body (23) that is constituted by a hollow member having a distal end opening (22) and a proximal end opening (21), and has a proximal end portion (25) to be installed on the distal end portion of the endoscope a first slit (31) that is formed in the cap body (23) and into which tissue is to be drawn, and that extends in a first direction from the distal end opening (22) and a second slit (32) that is formed in the cap body (23) and into which tissue is to be drawn, and that is connected to the first (31) slit and extends in a second direction differing from the first direction.
