A connecting plate has: bus bars which connect a plurality of batteries; a voltage-detection terminal unit which is connected to the bus bars and through which a voltage of a desired one of the batteries is detected; an electric wire connected to the voltage-detection terminal unit; and a molded resin board to which these components are integrally fixed. In the voltage-detection terminal unit, a device mounting portion onto which a circuit protecting device is to be mounted is integrally formed between an overlap contact portion opposed to the bus bar, and an electric wire connecting portion. Resin leakage preventing pieces for the bus bars are formed at side edges of the overlap contact portion. A device mounting portion is exposed to an outside through a device mounting window which is opened in the molded resin board, and a circuit protecting device is housed in the device mounting window.