When a power amplifier mounted in mobile communications equipment, such as a mobile-phone, is composed of a balanced amplifier, technology with which the loss of the electric power composition in a power combiner can be reduced is provided. According to the technical idea of the present embodiment, by dividing an isolation capacitor element into two capacitor elements with high symmetry and coupled in parallel, it is possible to make almost equal parasitic capacitance arising from these capacitor elements, even when the capacitor elements are formed as interlayer capacitor elements of the wiring substrate.