PURPOSE: To prevent a movable blade from tilt moving while decreasing resistance in a slide part due to a difference between right/left forces of the movable blade from a cutting start to a cutting end, by using a parallel link for supporting the thin plate-shaped movable blade having a cutting edge of hollowing an edge point line into a V shape.

CONSTITUTION: A movable blade 1, movable blade material 11, movable blade base metal 13 and a spacer 16 are fastened by using a supporting shaft pin 13 and a plate nut 17 and built, to fix a fixed blade 4 to a side of a paper through window 21 provided in a frame 2 to make a cut sheet pass. Supporting pins 22, 23 are secured to an end part of this frame 2, and supporting pins 14, 15 provided in the movable blade 1 are connected by the first/second links 31, 32 respectively formed with a parallel link 3, to support the movable blade l to the frame 2. Drive force is loaded to the supporting pin 14, to cut a sheet material by downward moving the movable blade 1 in the case of swiveling the parallel link 3 around the supporting pin 14.