An image forming apparatus including an optical scanning device that scans an object to be scanned with a beam in a main scanning direction includes a first rotation fulcrum unit and a second rotation fulcrum unit that are respectively provided in the optical scanning device on one side and on the other side in an orthogonal direction orthogonal to the main scanning direction. The first rotation fulcrum unit is provided outside a scanning area of the beam in the main scanning direction. The optical scanning device is provided rotatably around a virtual rotation axial line connecting the first rotation fulcrum unit and the second rotation fulcrum unit.