To make it possible to execute single sheet cutting with respect to many kinds varying in thicknesses by rotating a rotary type dial to rotate an eccentric cam, sliding a slide plate in compliance with the rotation of the cam and putting the blade edge of a cutter mounted at the front end of the slide plate into and out of a body.

Molded goods formed by integrating the selection dial 3 and the eccentric cam 4 are housed from laterally bisected covers 2 into the body freely rotatably around a revolving shaft 11 and the slide plate 5 is housed therein freely advanceably and retreatably in its longitudinal direction. The slide plate 5 is engaged and inserted with the revolving shaft 11 of the selection dial 3 into a long hole 10 disposed in its intermediate part. The eccentric cam 4 is brought into tight contact with projecting ribs 9 integrally molded at the front and rear ends of the slide plate 5. The cutter blade 6 is freely attachably and detachably mounted at the front end of the slide plate 5 and the projection quantity of the blade edge of the cutter blade 6 is continuously selected in tune with the eccentricity of the eccentric can 4 accompanying the rotation of the selection dial 3 by the rotation manipulation of the dial.