The present invention has for its object to provide a bias circuit capable of handling multiple frequency bands, which has a low number of parts and can be miniaturized. As a solving means therefor, the bias circuit of the present invention comprises: a first reactance means 2 and a second reactance means 5, one end each of which is connected to a bias point 210 to which an alternating current signal is supplied; a capacitive means 3 connecting the other end of first reactance means 2; and a direct-current circuit 4 supplying a direct-current bias signal to the connection point of first reactance means 2 and capacitive means 3. Then, the reactance values of first and second reactance means 2, 5 have been set so as to make the combined admittance, seen from the alternating current signal supply point toward the side of first reactance element 2 and second reactance element 5, zero.
