An exposure device configured to perform exposure using a plurality of light beams and capable of stabilizing image density without increasing circuit size. The exposure device has a first light source for emitting a first light beam and a second light source for emitting a second light beam. The exposure device exposes a photosensitive drum such that areas exposed to the respective first and second light beams at least partially overlap each other. A first drive current having a predetermined value and a second drive current are supplied to the respective first and second light sources. A photodiode detects the intensities of the respective first and second light beams or the sum of the intensities. The second drive current is controlled based on a detection result from the photodiode such that the sum of the intensities becomes equal to a target intensity.