An image forming apparatus includes an apparatus main body, a plurality of optical scanning devices, first temperature detectors for detecting the temperatures of the optical scanning devices, a second temperature detector for detecting the temperature of the apparatus main body, a first condition judger, a second condition judger and a temperature adjuster. The temperature adjuster performs a total motor drive process for driving the motors of all the optical scanning devices if a predetermined first condition is satisfied and a predetermined second condition is satisfied. On the other hand, the temperature adjuster drives the motor of the one optical scanning device and does not drive the motors of all the optical scanning devices excluding the one optical scanning device if the first condition is satisfied, but the second condition is not satisfied.