A processing device comprising: a processing unit accommodated in a housing and configured to process a medium; and a medium receiving unit that receives the medium discharged from the housing, the medium receiving unit including: a sheet-shaped receiving member; a rotating shaft provided inside the housing and to which one end of the receiving member is coupled; an operating portion provided separably from the housing and to which the other end of the receiving member is coupled; a pair of support portions that protrude from the housing in a retractable manner and support both ends of the operating portion; characterized by a rack provided on at least one of the pair of support portions; a rotating shaft gear provided on the rotating shaft and configured to rotate in conjunction with movement of the rack; and a speed increasing mechanism provided between the rack and the rotating shaft gear and configured to increase a rotation speed of the rotating shaft gear so that a feeding amount of the receiving member is greater than a movement amount of the pair of support portions, wherein the receiving member is wound around the rotating shaft and accommodated inside the housing when the operating portion is mounted on the housing, and the receiving member is fed from the rotating shaft so as to receive the medium when the operating portion is separated from the housing. a processing unit accommodated in a housing and configured to process a medium; and a medium receiving unit that receives the medium discharged from the housing, the medium receiving unit including: a sheet-shaped receiving member; a rotating shaft provided inside the housing and to which one end of the receiving member is coupled; an operating portion provided separably from the housing and to which the other end of the receiving member is coupled; a pair of support portions that protrude from the housing in a retractable manner and support both ends of the operating portion; characterized by a rack provided on at least one of the pair of support portions; a rotating shaft gear provided on the rotating shaft and configured to rotate in conjunction with movement of the rack; and a speed increasing mechanism provided between the rack and the rotating shaft gear and configured to increase a rotation speed of the rotating shaft gear so that a feeding amount of the receiving member is greater than a movement amount of the pair of support portions, wherein the receiving member is wound around the rotating shaft and accommodated inside the housing when the operating portion is mounted on the housing, and the receiving member is fed from the rotating shaft so as to receive the medium when the operating portion is separated from the housing. a sheet-shaped receiving member; a rotating shaft provided inside the housing and to which one end of the receiving member is coupled; an operating portion provided separably from the housing and to which the other end of the receiving member is coupled; a pair of support portions that protrude from the housing in a retractable manner and support both ends of the operating portion; characterized by a rack provided on at least one of the pair of support portions; a rotating shaft gear provided on the rotating shaft and configured to rotate in conjunction with movement of the rack; and a speed increasing mechanism provided between the rack and the rotating shaft gear and configured to increase a rotation speed of the rotating shaft gear so that a feeding amount of the receiving member is greater than a movement amount of the pair of support portions, wherein the receiving member is wound around the rotating shaft and accommodated inside the housing when the operating portion is mounted on the housing, and the receiving member is fed from the rotating shaft so as to receive the medium when the operating portion is separated from the housing.