A circuit board includes a board, circuitry provided on the board that supplies electric power to a motor, a positive-electrode-side power source terminal portion connected to a positive electrode terminal of the circuitry, and a negative-electrode-side power source terminal portion connected to a negative electrode terminal of the circuitry. The circuitry includes a first capacitor connected to the positive-electrode-side power source terminal portion, and a second capacitor connected to the negative-electrode-side power source terminal portion. The first and second capacitors are connected in series between the positive-electrode-side and the negative-electrode-side power source terminal portions. The board includes a through hole, at least a portion of which is between at least two of the first capacitor, the second capacitor, the positive-electrode-side power source terminal portion, and the negative-electrode-side power source terminal portion.