A rotating shaft of a rotary compressor that is rotatably supported with respect to a casing having a compression chamber therein and is rotationally driven around an axis to allow a fluid to be compressed with lubricating oil, the rotating shaft comprising: a shaft main body that extends in a rod shape around the axis; a main shaft piston rotor that is eccentrically provided at the shaft main body and is accommodated in a first compression chamber in the compression chamber; a sub-shaft piston rotor that is disposed apart in a direction of the axis from the main shaft piston rotor, is provided eccentrically with respect to the shaft main body in a direction different in phase by 180 degrees from the main shaft piston rotor, and is accommodated in a second compression chamber in the compression chamber; and an intermediate shaft part around which the lubricating oil is present and which is provided at a position sandwiched between the main shaft piston rotor and the sub-shaft piston rotor in the shaft main body, wherein the intermediate shaft part protrudes in a direction intersecting an eccentric direction of the main shaft piston rotor and the sub-shaft piston rotor as viewed in a cross section orthogonal to the axis, and has a pair of apexes where a distance between the outer peripheral surface and the axis is maximized on an outer peripheral surface of the intermediate shaft part, characterised in that the pair of the apexes is provided at positions symmetrical to each other with respect to the axis, and wherein the intermediate shaft part has a shape in which only a portion of the outer peripheral surface of the intermediate shaft part on a forward side of the rotational direction with respect to each apex is partially cut off radially inward from one region where an outer peripheral edge of the main shaft piston rotor and an outer peripheral edge of the sub-shaft piston rotor overlap each other, when the intermediate shaft part is viewed in a cross section orthogonal to the axis such that each apex is disposed at a position shifted at an angle larger than 0 degrees and smaller than 45 degrees toward a backward side in a rotational direction with respect to an imaginary line passing through the axis orthogonally to the eccentric direction. a shaft main body that extends in a rod shape around the axis; a main shaft piston rotor that is eccentrically provided at the shaft main body and is accommodated in a first compression chamber in the compression chamber; a sub-shaft piston rotor that is disposed apart in a direction of the axis from the main shaft piston rotor, is provided eccentrically with respect to the shaft main body in a direction different in phase by 180 degrees from the main shaft piston rotor, and is accommodated in a second compression chamber in the compression chamber; and an intermediate shaft part around which the lubricating oil is present and which is provided at a position sandwiched between the main shaft piston rotor and the sub-shaft piston rotor in the shaft main body, wherein the intermediate shaft part protrudes in a direction intersecting an eccentric direction of the main shaft piston rotor and the sub-shaft piston rotor as viewed in a cross section orthogonal to the axis, and has a pair of apexes where a distance between the outer peripheral surface and the axis is maximized on an outer peripheral surface of the intermediate shaft part, characterised in that the pair of the apexes is provided at positions symmetrical to each other with respect to the axis, and wherein the intermediate shaft part has a shape in which only a portion of the outer peripheral surface of the intermediate shaft part on a forward side of the rotational direction with respect to each apex is partially cut off radially inward from one region where an outer peripheral edge of the main shaft piston rotor and an outer peripheral edge of the sub-shaft piston rotor overlap each other, when the intermediate shaft part is viewed in a cross section orthogonal to the axis such that each apex is disposed at a position shifted at an angle larger than 0 degrees and smaller than 45 degrees toward a backward side in a rotational direction with respect to an imaginary line passing through the axis orthogonally to the eccentric direction.