A bus bar device 1 includes a bus bar 2 connected to a battery post 52 provided in a battery 50, an insulative housing 3 that covers the bus bar 2, a circuit board 5 attached to the housing 3 and an electronic parts 4 mounted on the circuit board 5. The bus bar 2 includes a first flat plate part 9 having a battery attaching part 13 to which the battery post 52 is attached, a second flat plate part 11 having a first parallel part 16 parallel to the first flat plate part 9 and an electric wire connecting part 21 extended from the first parallel part 16 to connect a terminal fitting of an electric wire connected to a load and a third flat plate part 10 provided between the second flat plate part 11 and the first flat plate part 9 and arranged in parallel with the circuit board 5. The third flat plate part 10 is provided in a direction intersecting the first flat plate part 9.