To clean stain on a lens caused by white turbidity. A turbidity degree calculating unit (40) calculates a degree of the white turbidity U on a surface of the lens (12) based on a brightness gradient g of an image I (x, y), and a lens cleaning control unit (60) sets a lens cleaning mode for spraying the cleaning fluid (114) or the compressed air (120), which is performed by the lens cleaning unit (70), based on the calculated turbidity degree U.
