An objective lens system opposing an imaged surface of semiconductor device, and imaging lens system arranged between this objective lens system and image sensor is used to inspect a lower component of the semiconductor device without being influence by an upper component. The F value of objective lens system is made into 1.5 or less, and an imaged surface is photographed and inspected. The imaging lens system also has several lenses with different focal distances. According to the desired magnification, a predetermined lens among the plurality of lenses is arranged in the predetermined location of an optical axis, and the other lenses are evacuated from an optical axis.