(57) An image forming apparatus includes an image forming unit (1); a binding unit (30) provided adjacent to the image forming unit (1); a a control unit (60) for controlling the image forming unit (1) and the binding unit (30) which forbids the operation of either one of these units during the operation of the other; a timer for measuring the binding operation time; a monitor which indicates operating conditions of the image forming unit and the binding unit and which functions as a timer display; a temperature measuring unit for measuring a reference temperature for the binding unit (30); and a time setter which adjusts the operation time of the binding unit (30) accordingly. In this apparatus, the monitor indicates the operating conditions of both the image forming unit (1) and the binding unit (30), allowing an operator to learn the binding status easily. Since the control unit (60) forbids operation of either the image forming unit (1) or the binding unit (30) during operation of the other unit, excessive consumption of electric power is prevented. The operation time of the binding unit is set according to the reference temperature. Consequently, even if there is a change in the ambient temperature, an operation time appropriate to the temperature will be set, and a good quality binding process will be ensured.