A disclosed human body detecting device includes a human body detector configured to detect a human body, and an electric power supply status switching part configured to switch a first shifting mode to a second shifting mode when the human body detecting device is not operated, and the human body detector continuously detects the human body for a predetermined time. The first shifting mode indicates a first status shifting to a second status based on a first condition in which the human body is detected by the human body detector, the second status representing electric energy consumption less than electric energy consumption of the first status, and the second shifting mode indicates the first status shifting to the second status based on a second condition other than the first condition.