PURPOSE: To provide a lapping device whereby even higher accuracy of a work to be lapped can be obtained by revolving the work to be lapped while rotating to lap the both surfaces of the work to be lapped between upper and lower level blocks.

CONSTITUTION: In a device, a work to be lapped (a) is provided between a lower level block 1 and an upper level block 2, and its both surfaces are lapped. The device is provided with a sun gear 5 connected to a drive source and an internal gear 6 provided on the outer peripheries of these level blocks. Also it is provided with a large carrier 7 which is provided with an outer gear meshed with a gear 6a of the internal gear 6 and the sun gear and revolves while rotating by the rotational driving of the sun gear, multiple carriers 8 which is provided with a gear meshed with the inner gear of the large carrier 7 and on which a work to be lapped is mounted, and a small sun gear 9 which is meshed with the gear of all these small carriers 8 and functions as the rotating center for rotation of the small carriers 8.