PURPOSE: To prevent contact with a work at movement between faces to be worked for working the part positions to be worked of the work having a plurality of faces to be worked.

CONSTITUTION: In a working method to work a work such as an automobile body 1 having a plurality of faces to be worked such as coated surfaces, by detecting means such as mark detecting cameras S1,S2,S3 provided on the upper stream side of working means such as grinding tools T1,T2,T3, a part position to be worked is detected, distinguished, and memorized at every face to be worked, after working by the working means at the every face to be worked based on data from the detecting means, transferred to another face to be worked, and controlled to be transferred to the part position to be worked of the face to be worked.