To provide an image forming apparatus for realizing effective use of energy and power consumption saving.

The image forming apparatus is provided with an input means for exhaust heat of a fuel cell installed inside or outside the image forming apparatus and heats an inside unit by the exhaust heat. Alternatively, the image forming apparatus comprises a heat input means for inputting the exhaust heat of the fuel cell installed inside or outside and a temperature control means heating the inside unit by a first heating means performing heating using the input the exhaust heat and a second heating means performing heating using electric power, wherein a first temperature detecting means detecting the exhaust heat input to the heat inputting means and a second temperature detecting means detecting the temperature of the inside unit are provided, and when the detected temperature value of the first temperature means is lower than the temperature value of the inside unit which is indicated beforehand, the second heating means is driven by the temperature control means so that the second temperature detecting means detects the temperature value which is indicated beforehand.