A transducer, and a method for manufacturing the transducer are provided. The transducer includes a substrate-side electrode provided in one side of an insulative substrate and an opposite plate including an opposite electrode disposed opposite to the substrate-side electrode, and which performs a function such as a reduction in impedance, conversion of capacitance, signal amplification, thereby achieving size reduction of the transducer itself. An upper plate is made of a silicon monocrystal and is arranged so as to face a substrate-side electrode. In the upper plate, an integrated circuit section which is an impurity region of an IC circuit is formed by a thermal diffusion method or an ion implantation method. By this transducer, an improvement in conversion efficiency, an improvement in productivity, and a size reduction of a mount system are achieved.