To secure such a cutter mechanism that is easy for working and assembling, besides being inexpensive in cost by providing a stationary cutter made of cold-rolled steel doubling as a mount part where a cut sheet is set up so as to traverse this cut sheet, and installing a circular rotary cutter rotatably pivoted to a cutter holder so as to cross as far as a specified amount with an edge of the stationary cutter.

A motor installed in one end of a stationary cutter 1 is rotated counterclockwise, and when an endless wire rolled on a driving pulley is made into running, a cutter holder 2 is pulled and shifted along the stationary cutter 1. At this time, a rotary cutter 3 is rotated at a constant period in accordance with a movement of the cutter holder 2 and in reverse against the traveling direction of the cutter holder 2, whereby the cutting of paper guided to a cutting point is carried out by an inlet guide part and another guiding part additionally installed in the cutter holder 2. If cutting gets starting, a cut piece of the paper is guided downward so as to straddle the stationary cutter 1 by the inductive guiding part made into a downwardly gentle inclined form. After cutting completion, the motor is rotated in reverse, and the cutter holder 2 is reset to the original position.