To provide an optical scanning device capable of scanning with a simple configuration.It includes a laser unit 10 for emitting a light beam, a laser control unit 42 for adjusting the light beam emitted by the laser unit 10, first and second prism units 20 and 30 through which an incident light beam is passed as a scanning beam, an angle between the incident light beam and the scanning beam being variable, and a prism control unit 44 for supplying an instruction to the first and second prism units 20 and 30 in order to change the angle between the incident light beam and the scanning beam. The first and second prism units 20 and 30 receive the light beam emitted by the laser unit 10 and emerge the scanning beam according to an instruction from the prism control unit 44 about the incident light beam.