A sheet-shaped hollow fiber membrane module includes a casing having a flat shape, the casing including a supply port and a discharge port, and a plurality of hollow fiber membranes accommodated inside the casing. The casing includes a plurality of the supply ports on one main surface of the casing and a plurality of the discharge ports on the other main surface of the casing, at least one of the plurality of the supply ports is closable, and at least one of the plurality of the discharge ports is closable. Each of the plurality of hollow fiber membranes includes a first opening at one end of the hollow fiber membrane and a second opening at the other end of the hollow fiber membrane, and the first opening and the second opening communicate with an outside of the casing and do not communicate with an inside of the casing.