An image forming apparatus incudes a driving unit configured to drive a light-emitting element for emitting a laser beam; a rotational polygon mirror scans a photosensitive member with the laser beam. The driving unit executes a first adjustment for causing the light-emitting element to emit light at a first light emission intensity to adjust a first driving current, and a second adjustment for causing the light-emitting element to emit light at a second light emission intensity to adjust a second driving current. During a time period after the polygon mirror has started rotating until a predetermined speed is reached, the driving unit performs the first adjustment and the second adjustment, after the polygon mirror has started rotating and before performing the first adjustment, performs the second adjustment.