An image forming apparatus includes an intruder detecting unit that detects an intruder, a notification unit that notifies detection of the intruder, an intruder detection mode execution unit that executes an intruder detection mode to cause the notification unit to notify the detection of the intruder if the intruder is detected with the intruder detecting unit operating, a job reception unit that receives an instruction to perform a job, and an image forming unit that forms an image. The intruder detection mode execution unit suspends the intruder detection mode for a predetermined suspension time period if the job reception unit receives the instruction to perform a predetermined specific job while the intruder detection mode execution unit executes the intruder detection mode.