PURPOSE: To obtain a pump device capable of moving a viscous fluid well with a simple, small, light-weight and inexpensive structure by providing a unit with entry and exit mouths for the fluid and rotating parts for moving the fluid between the entry and exit mouths in the unit.

CONSTITUTION: A pump device comprises a drive shaft 11 which extends to a receiving element 12 and is rotatably supported on a support member 13. A unit with entry and exit mouths for the fluid received in the receiving element 12 is provided. The unit comprises a first plate element 14 rotating with the drive shaft 11 and a second plate element 15 secured on the receiving element 12. A spiral recess 20 eccentric with respect to the drive shaft 11 is formed on a surface of the second plate element 15 facing a flat transversal surface 16 of the first plate element 14. A sleeve element 23 is fitted in the space defined between the drive shaft 11 and the second plate element 15. At least one passageway 25 is formed from the upper outer side of the sleeve element 23.