A light scanning device for performing laser beam scanning, which includes a polygon scanner configured to deflect a laser beam; an optical device configured to guide the deflected laser beam; a case in which the polygon scanner and the optical device are arranged; a transparent covering member which is provided on the case to cover an opening and which transmits the laser beam to perform laser beam scanning; and a cleaner which is detachably attached to the light scanning device and which includes an elastic cleaning member on one side of a body of the cleaner for cleaning a surface of the transparent covering member, wherein the body of the cleaner has a recessed portion on the one side thereof.