To accurately position an openable fixed blade unit 81 for fixedly arranging a fixed blade 51 corresponding to a movable blade unit 71 for arranging a movable blade 53 to make a shearing operation.

A first butted surface 12 corresponding to an operating direction of a reciprocative stroke of the movable blade 53 and a second butted surface 13 corresponding to an opening direction of the fixed blade unit 81 are formed on the movable blade unit 71 fixedly arranged. A first butting surface 22 abuttingly positioning on the first butted surface 12 in a closed state of the fixed blade unit 81, and a second butting surface 23 abuttingly positioning on the second butted surface 13 in the closed state of the blade unit 81 are formed on the openably arranged fixed blade unit 81. The accurate positioning is made possible by abutting and engagingly holding respective butting surfaces 22 and 23 for respective abutted surfaces 12 and 13.