A circuit board in which end faces (36a) of wires are located in positions withdrawn from the end in a joint region of a first board (31a), end faces (36b) of wires are located in positions withdrawn from the end in a joint region of a second board (31b), a gap (W) between the end faces (36a) of the wires of the first board (31a) and the end faces (36b) of the wires of the second board (31b) is filled with a conductor (16A), and the first board (31a) and the second board (31b) are jointed by means of a resin.