PURPOSE: To smoothly and accurately regulate the direction of a transfer paper by providing a control means for moving a regulating means to a position which is wider than the width of a latent image obtained from the width of an original and copying magnification after a fixed time decided by a timer means.

CONSTITUTION: A paper width regulating plate 301 is moved by a paper width regulating plate driving motor 302. The motor 302 is controlled by a controller 303. A light shielding plate 304 intercepts a photosensor 305 when the plate 301 is moved to the outside. A position obtained at this time is set as a reference position for control, and the control is executed. Based on paper size information being only the width of the original and the set copying magnification, timing for moving the plate 301 of a paper supply tray so that optimum paper width may be obtained before starting copying is set as the fixed time after settling the data, whereby accurate and smooth processing is executed without unnecessary movement.