Abstract: A clear view screen (11) comprises a fixed frame (5), a rotating frame (7) and an induction motor (22). The fixed frame (5) has an inner peripheral surface (6) with a V-shaped section, where slits (33) are provided. The rotating frame (7) has an outer peripheral surface (8), which is also V-shaped in section. Compressed air blows into the slits (33) through an air path (35) and an air supply pipe (17), so that the rotating frame (7) is supported rotatably within the fixed frame (5). In this state, the rotating frame (7) is rotated by means of the induction motor (22). As a result, waterdrops and the like adhering to a transparent plate (9) provided in the rotating frame (7) can be removed by centrifugal force.