An object of the present invention is to provide an antiviral agent which exhibits high antiviral activity even under irradiation with visible light and is capable of detoxifying a virus. The sensor cell is preferably coupled so that it shares the negative current collector with last fuel cell in the in-plane fuel cell assembly, and is short-circuited by a resistor to provide a voltage signal, indicative of the status of the assembly in operation. Opening the first fascia portion also enables access to an actuator which enables moving a second fascia portion for conducting service activities.