To provide a vane pump simply disassembled and assembled, and hardly causing liquid leakage in a liquid sealing member even when the disassembling and assembling are repeated.

The vane pump 1 is constituted that a rotor shaft 9 is divided into a rotor side shaft 9A protruded from a rotor 8 and a drive side shaft 9B connected with a motor M, and is equipped with an engagement means 73 engageably/disengageably connecting the rotor side shaft 9A and the drive side shaft 9B. A first bearing 28 rotatably supporting the rotor side shaft 9A is attachably/detachably disposed in a bearing mounting hole 43 formed on one side plate 6, and a second bearing 74 rotatably supporting the drive side shaft 9B is disposed at the farther position from the rotor 8 than the first bearing 28 on the side plate 6. The drive side shaft 9B is liquid-sealed by a liquid sealing member 37 disposed on the bearing mounting hole 43.