Not to leave a circular arc scratching cutting trace on a specular finished surface of a synthetic resin plate.

A shaft center of a rotor 1 is set so that an angle a made by the shaft center and a laminated wood end surface 91 to be cut becomes an acute angle and a rectilinear knife edge 31 of a cutting blade 3 makes linearly contact with the plate end surface 91 under a method to work the end surface 91 of a soft plate 9 by cutting it extremely thin by the cutting blade 3 installed on the rotor 1 rotating at a constant position while rectilinearly moving the synthetic resin plate 90 at constant speed.