PURPOSE: To efficiently perform copy operation and bookbinding operation by mounting a control means prohibiting image forming operation during heating operation and permitting the same after the completion of heating operation in a bookbinding means.

CONSTITUTION: In an image forming apparatus, an image forming part 8 forms an image on paper. A bookbinding means 30 performs heating and cooling operations with respect to a bookbinding object. In image forming operation and bookbinding operation, a control means 60 prohibits image forming operation by the image forming part 8 during the heating operation in the bookbinding operation. By this constitution, excessive power consumption due to the simultaneous execution of the heating operation of the bookbinding means 30 and the image forming operation of the image forming part 8 is prevented. After the heating operation in the bookbinding means 30 is completed, the control means 60 permits the image forming operation through the image forming means 8. By this method, image forming operation can be performed even during the cooling operation in the bookbinding means 30 and copy operation and bookbinding operation can be efficiently performed.