To provide a vane compressor with little abrasion of vanes even in increased revolution speed, and highly efficiently operable over a long period.

Slide grooves 16 are formed to a vane holding member 14 attached to a drive rotational shaft 12 to axially movably receive the vanes 18. Cam end surfaces 20X, 22X are formed to cam members 20, 22, at a constant distance between circumferentially corresponding positions for a whole circumference, and abut on both edges in an axial direction of the vanes 18. Axially slide engaging grooves 26 engaged with external edges of the vanes 18 are formed on an inner circumferential surface of a casing inner member 24 rotatably supported with respect to casing outer members 2, 4, 6. A first or a second annular cavity is formed by a vane holding member large diameter part 14a, a vane holding member small diameter part 14b or 14c, the cam end surface 20X or 22X, and a casing inner member 24, and the first or second annular cavity is partitioned by the vanes 18 to form a plurality of first or second partition chambers.