A rotor of a centrifugal compressor, comprising: a rotor main body extending in an axis direction and having a recessed part formed on an outer circumferential surface thereof; an impeller including: a cylinder part having a cylindrical shape extending around the axis and in which an inner circumferential surface having a fitting region tightly fitted to the outer circumferential surface of the rotor main body is formed; an annular disc extending from the cylinder part to a radial outer side with respect to the axis; a plurality of blades provided at intervals in a circumferential direction on a surface facing one side in the axis direction of the annular disc; and a cover covering the plurality of blades from the one side in the axis direction; and a contact member fitted into the recessed part and in which a part protrudes toward a radial outer side from the outer circumferential surface to come in contact with the cylinder part from the axis direction, wherein the contact member includes a plurality of segmented parts arranged in the circumferential direction with respect to the axis, characterized in that the inner circumferential surface of the cylinder part includes a non-fitting region adjacent to the fitting region in the axis direction and having an inner diameter larger than that of the rotor main body . a rotor main body extending in an axis direction and having a recessed part formed on an outer circumferential surface thereof; an impeller including: a cylinder part having a cylindrical shape extending around the axis and in which an inner circumferential surface having a fitting region tightly fitted to the outer circumferential surface of the rotor main body is formed; an annular disc extending from the cylinder part to a radial outer side with respect to the axis; a plurality of blades provided at intervals in a circumferential direction on a surface facing one side in the axis direction of the annular disc; and a cover covering the plurality of blades from the one side in the axis direction; and a contact member fitted into the recessed part and in which a part protrudes toward a radial outer side from the outer circumferential surface to come in contact with the cylinder part from the axis direction, wherein the contact member includes a plurality of segmented parts arranged in the circumferential direction with respect to the axis, characterized in that the inner circumferential surface of the cylinder part includes a non-fitting region adjacent to the fitting region in the axis direction and having an inner diameter larger than that of the rotor main body . a cylinder part having a cylindrical shape extending around the axis and in which an inner circumferential surface having a fitting region tightly fitted to the outer circumferential surface of the rotor main body is formed; an annular disc extending from the cylinder part to a radial outer side with respect to the axis; a plurality of blades provided at intervals in a circumferential direction on a surface facing one side in the axis direction of the annular disc; and a cover covering the plurality of blades from the one side in the axis direction; and a contact member fitted into the recessed part and in which a part protrudes toward a radial outer side from the outer circumferential surface to come in contact with the cylinder part from the axis direction, wherein the contact member includes a plurality of segmented parts arranged in the circumferential direction with respect to the axis, characterized in that the inner circumferential surface of the cylinder part includes a non-fitting region adjacent to the fitting region in the axis direction and having an inner diameter larger than that of the rotor main body . <EOS>