To provide an image forming apparatus for realizing a trial printing function for reducing to the utmost and avoiding wasteful consumption of time and expendables.

An image inputting/outputting system 100 is provided with a reader apparatus 200 for optically reading manuscript images for converting to image data; a printing apparatus 300 for feeding sheets, printing image data on the sheet as visible images, and ejecting the sheet to the outside of the apparatus; and a control apparatus 110 for controlling the reader apparatus 200 and the printing apparatus 300. When a trial copy is set in the formation of images according to a set copy mode, the number of trial prints is set according to set conditions, and trial printing for the set number of trial prints is performed.