The invention relates to an image forming apparatus and a method for controlling the same. The object of the invention is to provide the image forming apparatus matched with a low resolution level, other than the highest resolution level, in resolution levels corresponding to the resolution levels and the size of the beam on a sensitization body. Compared with the conventional technology, the developer consumption amount is furthermore suppressed and the density adjustment is conducted within a shorter period or when the same developer consumption amount and same time period is used for the density adjustment, the density adjustment control is conducted with a higher precision compared to the conventional density adjustment. The image forming apparatus is characterized in that: the image forming apparatus comprises an adjustment unit to conduct an exposure time-based density adjustment using a plurality of half-tone patterns prepared by changing an exposure time per pixel at a timing when a resolution level shifts from the low resolution level to the high resolution level and before actually shifting to an image forming operation executed at the high resolution level.