Abstract: The disclosed press processing method and device can chamfer work, for instance by pressing a chamfering tool against the work at a predetermined contact pressure, without detecting the pressing force of the chamfering tool against the work or without feedbacking the detected pressing force to a robot controller. The press processing device used being mounted on automatic mechanical processing means such a multi-joint robot, comprises: a processing section (e.g., grinder) (11) held by a support body (12) in such a way that pressure caused by a dead load of the processing section is not applied to a processing portion (e.g. blade) (11d) of the processing section (11); a constant torque applying section (e.g., servomotor) (16) for pivoting the processing section in a predetermined direction at a constant torque; and a mounting member (20) for mounting the constant torque applying section to a robot arm (R).