A light amount adjusting device includes: a first linear movement wing and a second linear movement wing respectively connected to a first side of a rotation center of the link and a second side opposite to the first side of the rotation center of the link, each of the first and second linear movement wings provided on the case and configured to linearly move in linear directions between a first position of the first linear movement wing; and a first rotation wing and a second rotation wing respectively connected to the link and rotatably coupled to the case so as to be rotated between a first position of the first and second rotation wings at which at least a portion of the aperture of the case is closed and a second position of the first and the second rotation wing at which the aperture of the case is opened.