PURPOSE: To provide possibility of performing a very delicate processing by installing a lapping material on the surface of a cylindrical member inflated with liquid.

CONSTITUTION: A roll 4 is rotated and put in contact with the processing surface of a work 8, and either the work 8 or roll 4 is reciprocated. Thus processing is carried out. Therein the lapping material 13 on the surface of a cylindrical member 1 inflated with a fluid 3 is put in contact with the surface of a base material 7 by the pressure of fluid, and in case there is partial undulation on the surface of the base material 7, the contact surface of the roll 4 with the base material 7 easily varies accordingly. Therefore, a minute projection of several μms can easily be removed without risk of excessive cutting. It is also possible to follow easily the undulation on the base material 7, and also is practicable to generate mild contacting with the base material 7.