An adhering matter determination portion includes an irradiation portion, a light receiving portion and a determination portion. The irradiation portion radiates a light to a plurality of different areas of a transparent plate. The light receiving portion converts reflected waves reflected at the different areas into electrical signals. The determination portion compares at least one of detection signals outputted from the light receiving portion with a determination threshold. When the detection signal is lower than the determination threshold, the determination portion determines that there is an adhering matter on the transparent plate. The determination portion compares the detection signals. When a difference of the detection signals is higher than a condensation determination value, the determination portion determines that the adhering matter is raindrops. When the difference of the detection signals is lower than the condensation determination value, the determination portion determines that the adhering matter is dewdrops.