A laser scanning device is provided to have an F-theta lens fixing device mechanically fixing an F-theta lens at a laser scanning device. A laser scanning device includes a protrusion section(141) formed at each end part of both sides of an F-theta lens(107). An inserting hole is formed at a mount(131) at which each end part of both sides of the F-theta lens is mounted. The inserting hole is formed by penetrating through the mount. A fixing unit(143) has a guiding groove formed by penetrating the mount with a predetermined length such that the guiding groove is communicated with the inserting hole. The protrusion section inserted into the inserting hole is coupled and fixed with the guiding groove. A stopper is mounted at an end part of the protrusion section to prevent the protrusion section from being separated from the guiding groove after the protrusion section is inserted into the guiding groove.
