To fix a work with a method, which can quickly reduce the machining error, by setting the relative positional relation of work vices for pinching a work end and an intermediate part thereof at the appropriate positional relation with the only operation for pinching a work with the vices.

A work 55 is strongly pinched by work vices 51a, 51d provided in both ends. In the case where position of the work vices 51c, 51d of the intermediate part are displaced from an appropriate position for pinching the work 55, the force for deforming the work 55 is applied, and the work vices 51b, 51c of the intermediate part are slid to the appropriate position for pinching the work 55 on a table 53 by the reaction force applied from the work 55. When the work 55 is strongly pinched by the work vices 51b, 51c of the intermediate part, the force of a presser surface for pressing a fixing flange is increased. As a result, the two work vices 51b, 51c of the intermediate part are strongly fixed to the table 53.