To provide a laser scanning optical unit in which a fixedly stuck scanning image forming device can demonstrate stable optical characteristics and in which this device and its optical housing can be individually utilized for recycling.

An optical housing 13 in this embodiment is equipped with: a plurality of fixing projections 32, 33, 34 for fixing to the optical housing 13, roughly the center part (fig. 2A) in the main scanning direction of the scanning image forming device (the device) 5; and supporting projections 30, 35 for supporting both ends (fig. 2B, C) in the main scanning direction of the element 5 device, respectively. The device 5 is fixedly stuck with an adhesive 31 to a part (one fixing projection 32 in the example) among the plurality of fixing projections located nearly in the center.