Provided is a technique capable of improving isolation characteristics between a plurality of signal paths through which RF signals pass, without using ground electrodes or the like. Wiring electrodes 10a and 20a through which RF signals do not pass simultaneously are formed so as to be adjacent to each other in a central region of a component mounting surface 2a of a circuit board 2, and wiring electrodes 11a and 21a through which RF signals pass simultaneously are formed so as to be distanced from transmission paths 10 and 20. Accordingly, the RF signals do not simultaneously pass through the transmission paths 10 and 20, which are disposed near each other, and thus there is no risk that the RF signal passing through one of the signal paths will interfere with the RF signal passing through the other signal path.