A printing unit comprises: a platen unit including a platen roller configured to feed a recording sheet; and a head unit including a thermal head configured to perform printing on the recording sheet, the head unit being separably combined with the platen unit, the head unit including: a head frame; a cutter mechanism mounted to the head frame in a removable manner, the cutter mechanism being configured to cut the recording sheet; a support member provided between the cutter mechanism and the head frame, the support member being movable between a coupled position at which the cutter mechanism is coupled to the head frame and a decoupled position at which the cutter mechanism is detachable from the head frame; and a first urging member interposed between the thermal head and the support member, the first urging member being configured to urge the thermal head toward the platen roller, and to urge the support member toward the coupled position.