To provide a photosensor device capable of miniaturizing its conformation, while being equipped with a rain sensor and an illuminance sensor inside the same casing.

This photosensor device 100, equipped with the rain sensor and the illuminance sensor in the same casing, has a constitution wherein a light-receiving element 21 is used in common for the rain sensor and the illuminance sensor, and a light-emitting pattern of a light-emitting element 11 constituting the rain sensor is controlled by a control part 30; and the output of the light-receiving element 21 is switched to the rain sensor output or to the illuminance sensor output according to the light emitting pattern. Since the light-receiving element 21 is used in common, in this way, the conformation of the photosensor device 100 can be miniaturized.