An inspection system includes a light source, a mirror, Galvano mirrors, a casing that holds the mirror and the Galvano mirrors inside and includes an attachment portion for attaching an optical element, and a control unit that controls a deflection angle of the Galvano mirrors, wherein the control unit controls the deflection angle so that an optical path optically connected to a semiconductor device is switched between a first optical path passing through the Galvano mirrors and the mirror, and a second optical path passing through the Galvano mirrors and the attachment portion, and controls the deflection angle so that the deflection angle when switching to the first optical path has been performed and the deflection angle when switching to the second optical path has been performed do not overlap.