A vane compressor comprising: - an approximately cylindrical cylinder whose axial ends are open; - a frame that closes one of the axial ends of the cylinder; - a cylinder head that closes the other axial end of the cylinder, - a rotor shaft including a columnar rotor portion that rotates in the cylinder about a central axis that is eccentric to the central axis of an inner peripheral surface of the cylinder, and a rotary shaft portion (4b, 4c) that transmits torque to the rotor portion and is supported by the frame and cylinder head; and - a plurality of vanes (9, 10) installed in the rotor portion, each of the plurality of vanes having a tip portion (9a, 10a) formed in a circular arc shape facing outward, wherein - a bush holding portion (4d, 4e) having an approximately circular cross-section and penetrating in an axial direction is formed in a vicinity of an outer peripheral portion of the rotor portion, - each of the plurality of vanes (9, 10) is supported through a pair of approximately semicolumnar bushes (11, 12) in the bush holding portion (4d, 4e) so as to be rotatable and movable with respect to the rotor portion in the rotor portion so that a compression operation is performed in a state where a longitudinal direction of each of the plurality of vanes (9, 10) and a normal direction of the inner peripheral surface of the cylinder are constantly coincident with each other; - a plurality of partial-ring-shaped vane aligners (5, 6, 7, 8), each vane aligner is unitarily formed with an end of each of the plurality of vanes (9, 10) such that a center line of each of the plurality of vanes (9, 10) passes through an approximately central axis of a circular arc constituting a partial ring shape of each of the vane aligners (5, 6, 7, 9), a concave portion or a ring-shaped groove (2a, 3a) being concentric with an inner peripheral surface of the cylinder is formed in an end surface of each of the cylinder head and the frame on a side of the cylinder, the vane aligners (5, 6, 7, 8) are fitted in the concave portion or the ring-shaped groove (2a, 3a), and - an angle α of the circular arc constituting the partial ring shape of each of the vane aligners (5, 6, 7, 8) satisfies a relationship of Equation: α < 2 tan − 1 R sin π N R cos π N + e where R is a distance between a centre of rotation of the bushes (11, 12) and a centre of rotation of the rotor portion, e is a distance between a central axis of the inner peripheral surface of the cylinder and the centre of rotation of the rotor portion, and N is a number of the plurality of vanes (9, 10), characterised in that a minute space is maintained between the tip portion (9a, 10a) of each of the plurality of vanes (9, 10) and the inner peripheral surface of the cylinder. - an approximately cylindrical cylinder whose axial ends are open; - a frame that closes one of the axial ends of the cylinder; - a cylinder head that closes the other axial end of the cylinder, - a rotor shaft including a columnar rotor portion that rotates in the cylinder about a central axis that is eccentric to the central axis of an inner peripheral surface of the cylinder, and a rotary shaft portion (4b, 4c) that transmits torque to the rotor portion and is supported by the frame and cylinder head; and - a plurality of vanes (9, 10) installed in the rotor portion, each of the plurality of vanes having a tip portion (9a, 10a) formed in a circular arc shape facing outward, wherein - a bush holding portion (4d, 4e) having an approximately circular cross-section and penetrating in an axial direction is formed in a vicinity of an outer peripheral portion of the rotor portion, - each of the plurality of vanes (9, 10) is supported through a pair of approximately semicolumnar bushes (11, 12) in the bush holding portion (4d, 4e) so as to be rotatable and movable with respect to the rotor portion in the rotor portion so that a compression operation is performed in a state where a longitudinal direction of each of the plurality of vanes (9, 10) and a normal direction of the inner peripheral surface of the cylinder are constantly coincident with each other; - a plurality of partial-ring-shaped vane aligners (5, 6, 7, 8), each vane aligner is unitarily formed with an end of each of the plurality of vanes (9, 10) such that a center line of each of the plurality of vanes (9, 10) passes through an approximately central axis of a circular arc constituting a partial ring shape of each of the vane aligners (5, 6, 7, 9), a concave portion or a ring-shaped groove (2a, 3a) being concentric with an inner peripheral surface of the cylinder is formed in an end surface of each of the cylinder head and the frame on a side of the cylinder, the vane aligners (5, 6, 7, 8) are fitted in the concave portion or the ring-shaped groove (2a, 3a), and - an angle α of the circular arc constituting the partial ring shape of each of the vane aligners (5, 6, 7, 8) satisfies a relationship of Equation: α < 2 tan − 1 R sin π N R cos π N + e where R is a distance between a centre of rotation of the bushes (11, 12) and a centre of rotation of the rotor portion, e is a distance between a central axis of the inner peripheral surface of the cylinder and the centre of rotation of the rotor portion, and N is a number of the plurality of vanes (9, 10), characterised in that a minute space is maintained between the tip portion (9a, 10a) of each of the plurality of vanes (9, 10) and the inner peripheral surface of the cylinder.