A compressor includes a cylindrical casing, a bundle which includes a tubular stationary member and a rotor accommodated into the tubular stationary member, the bundle being configured to be inserted into an inner portion of the casing, and a roller configured to roll on an inner circumferential surface of the casing while supporting the bundle when the bundle is inserted into the inner portion of the casing along an axial direction. An outer circumferential surface of the roller is a continuous convex curved surface defined such that a curvature radius of an end side curved surface portion along a rotating shaft of the roller is smaller than a curvature radius of a center curved surface portion.