A method for machining a work in a work machining apparatus provided with a movable main spindle moving between a work supply position and a work take-out position, includes arranging a tool rest on the movable main spindle to move integrally with the movable main spindle, supplying the work at the work supply position to the movable main spindle, moving the movable main spindle from the work supply position toward the work take-out position, machining the work held on the movable spindle with a tool of the tool rest while moving the movable main spindle from the work supply position toward the work take-out position, and taking out the work at the work take-out position from the movable main spindle.