A circuit board includes: a power supply wiring board that includes a power supply circuit that outputs the power supply voltage, and a first power supply line and a second power supply line which are connected with the power supply circuit; a first wiring board that includes a first line; a second wiring board that includes a second line; a first cable that includes a first conductor that connects the first power supply line and the first line; a second cable that includes a second conductor that connects the second power supply line and the second line; and a short-circuit conductor that short-circuits the first line and the second line. An electrical length of a route from the power supply circuit to the first wiring board is shorter than an electrical length of a route from the power supply circuit to the second wiring board.