A translucent cover (1012) defines a lamp chamber (1013) together with a housing (1011) while forming a portion of an outer face of a vehicle. A LiDAR sensor (1161) is disposed in the lamp chamber (1013) to detect external information of the vehicle. A half mirror (1162) is disposed in the lamp chamber (1013) so as to cover the LiDAR sensor (1161) from a side where the translucent cover (1162) is disposed. The translucent cover (1012) has a first transparency to visible light. The half mirror (1162) has a second transparency to the visible light that is lower than the first transparency.