PURPOSE: To eliminate a mis-registration by releasing work clamps from a carriage while clamping the work and returning the carriage in an opposite direction, then fixing these work clamps again to the carriage and moving the carriage again in an ejection direction.

CONSTITUTION: The carriage 15 is supported freely movably in the ejection direction on a carriage base 7 provided freely movably in the direction orthogonal with the ejection direction. The work clamps 31a, 31b which clamp the work 25 are mounted freely adjustably in position to the above-mentioned carriage. The carriage is moved to the max. extent to move the work in the ejection direction. The work clamps are released from the carriage and are fixed to the carriage base while the work is held clamped. After only the carriage is returned in the opposite direction, the work clamps are fixed again to the carriage and the carriage is moved again in the ejection direction. As a result, the mis-registration of the work by the reholding of the work is eliminated.