An image forming apparatus including a fan disposed between an exhaust port and a filter, and a controller configured to perform at least one of first fan control and second fan control when at least one switching condition is satisfied among one or more switching conditions for switching fan control, the first fan control being for controlling the fan to generate an air current when an in-apparatus temperature detected by a temperature sensor is higher than a threshold temperature, the second fan control being for controlling the fan to generate an air current when an air contamination amount detected by a contamination sensor is larger than a threshold contamination amount.