An image forming apparatus includes a sensor configured to detect an original, a nonvolatile storage that includes a semiconductor area, a setting unit configured to execute a setting for dividing the semiconductor area into a plurality of areas, and a controller configured to execute Trim processing on the divided areas in response to passing of a predetermined time period while the image forming apparatus is in a standby state. The controller is configured to stop the Trim processing based on a detection of the original detected by the sensor while the Trim processing is executed.