An optical scanning device includes a holding member. The holding member has a boss part and an arm part that extends from the boss part in a direction perpendicular to the movement direction of the holding member and holds the cleaning member. The boss part is mounted with a posture correction member relatively movable in the movement direction of the holding member. The posture correction member is movably inserted into a groove between two second rail parts, and when the holding member moves, the posture correction member moves later than movement of the holding member, so that an inclined posture of the holding member is corrected by the delay operation in a direction perpendicular to the second rail part.