A bus bar module includes an insulating resin case mounted to an assembled battery and including a bus bar accommodating chamber, a conductive metal bus bar, and a voltage detection terminal. The assembled battery includes a plurality of cells in which a positive terminal and a negative terminal are alternately arranged. The positive terminal and the negative terminal are collectively disposed in the bus bar accommodating chamber. The conductive metal bus bar includes a plurality of terminal through holes corresponding to a number of the positive terminal and the negative terminal. The conductive metal bus bar is accommodated in the bus bar accommodating chamber.