A multi-beam scanning device in which generation of differences in scanning speed and curved image planes among a plurality of beams is prevented and pitch adjustment for the plurality of beams in the sub-scanning direction can easily be performed. Cylindrical lenses are provided on respective optical paths extending from a plurality of light sources to a beam splitter, and positions of the cylindrical lenses are adjusted by optical path correcting mechanisms for adjustment of position of the respective beams in the sub-scanning direction. A sensor section receives the respective beams to output to a control circuit a detection signal corresponding to a light receiving position. The control circuit drives an optical path correcting drive circuit based on a predetermined threshold and the output signal to control actions of the optical path correcting mechanisms.