A scroll compressor comprising: a rotating shaft that extends along an axis; a motor that rotates the rotating shaft; a scroll compression portion that compresses a refrigerant by the rotation of the rotating shaft; and a housing that houses the rotating shaft, the motor, and the scroll compression portion, wherein the scroll compression portion includes a fixed scroll that has a fixed end plate fixed to the housing, and a fixed wrap that protrudes from the fixed end plate in a direction of the axis, an orbiting scroll that is provided to the rotating shaft, and has an orbiting end plate disposed to face the fixed end plate in the direction of the axis, and an orbiting wrap that protrudes from the orbiting end plate toward the fixed end plate and forms a compression chamber for the refrigerant together with the fixed wrap, and an Oldham ring that supports the orbiting scroll such that the orbiting scroll orbits around the axis without rotating, the Oldham ring has a ring body that has an annular shape to surround the axis, and a plurality of keys (52, 53) that protrude from the ring body and are inserted into key grooves (41c, 44c) provided in the orbiting end plate and the fixed end plate, the orbiting end plate has a thick portion that has a disk shape and is provided with the orbiting wrap, and a thin portion which is integrally provided with the thick portion on an outer side of the thick portion in a radial direction, has an annular shape, and has a smaller thickness dimension in the direction of the axis than a thickness dimension of the thick portion, and of which an end face facing the fixed end plate side is disposed at a position away from the fixed end plate as compared with the thick portion, and the ring body is provided to be placed on the end face of the thin portion, the scroll compressor being characterized in that the Oldham ring is interposed between the fixed end plate and the orbiting end plate, and in that the key groove provided in the orbiting end plate is open on the outer peripheral surface of the thin portion and penetrates the thin portion in the direction of the axis. a rotating shaft that extends along an axis; a motor that rotates the rotating shaft; a scroll compression portion that compresses a refrigerant by the rotation of the rotating shaft; and a housing that houses the rotating shaft, the motor, and the scroll compression portion, wherein the scroll compression portion includes a fixed scroll that has a fixed end plate fixed to the housing, and a fixed wrap that protrudes from the fixed end plate in a direction of the axis, an orbiting scroll that is provided to the rotating shaft, and has an orbiting end plate disposed to face the fixed end plate in the direction of the axis, and an orbiting wrap that protrudes from the orbiting end plate toward the fixed end plate and forms a compression chamber for the refrigerant together with the fixed wrap, and an Oldham ring that supports the orbiting scroll such that the orbiting scroll orbits around the axis without rotating, a fixed scroll that has a fixed end plate fixed to the housing, and a fixed wrap that protrudes from the fixed end plate in a direction of the axis, an orbiting scroll that is provided to the rotating shaft, and has an orbiting end plate disposed to face the fixed end plate in the direction of the axis, and an orbiting wrap that protrudes from the orbiting end plate toward the fixed end plate and forms a compression chamber for the refrigerant together with the fixed wrap, and an Oldham ring that supports the orbiting scroll such that the orbiting scroll orbits around the axis without rotating, the Oldham ring has a ring body that has an annular shape to surround the axis, and a plurality of keys (52, 53) that protrude from the ring body and are inserted into key grooves (41c, 44c) provided in the orbiting end plate and the fixed end plate, a ring body that has an annular shape to surround the axis, and a plurality of keys (52, 53) that protrude from the ring body and are inserted into key grooves (41c, 44c) provided in the orbiting end plate and the fixed end plate, the orbiting end plate has a thick portion that has a disk shape and is provided with the orbiting wrap, and a thin portion which is integrally provided with the thick portion on an outer side of the thick portion in a radial direction, has an annular shape, and has a smaller thickness dimension in the direction of the axis than a thickness dimension of the thick portion, and of which an end face facing the fixed end plate side is disposed at a position away from the fixed end plate as compared with the thick portion, and a thick portion that has a disk shape and is provided with the orbiting wrap, and a thin portion which is integrally provided with the thick portion on an outer side of the thick portion in a radial direction, has an annular shape, and has a smaller thickness dimension in the direction of the axis than a thickness dimension of the thick portion, and of which an end face facing the fixed end plate side is disposed at a position away from the fixed end plate as compared with the thick portion, and the ring body is provided to be placed on the end face of the thin portion,