A circuit board is provided. The circuit board including a dielectric substrate; a ground electrode formed on the dielectric substrate; a radiation line formed on the dielectric substrate, at least a part of the radiation line including an open end and opposed to the ground electrode; a feeding line connected to the other end of the radiation line, the feeding line configured to feed high frequency signals to the radiation line or receive high frequency signals generated in the radiation line; a short-circuit line formed on the dielectric substrate and connected to the radiation line; a short-circuit element configured to short-circuit the short-circuit line and the ground electrode; and a connection terminal provided on the short-circuit line, wherein the connection terminal connects one end of the short-circuit element to the short-circuit line at a connection position and is configured so that the connection position is changeable.