An electronic component (encoder) including an operation body is mounted on a circuit board. The electronic component causes a controller to perform processing in accordance with an operation input by the operation body. The mounting board includes a power-feeding leg piece connected to a wireless communication processor so that high frequency communication is allowed, a first short-circuiting leg piece that is adjacent to the power-feeding leg piece via a cut-out portion, and a second short-circuiting leg piece separated from the power-feeding leg piece. The short-circuiting leg pieces are connected to grounded portions. The impedance is adjusted by appropriately selecting the width or the depth of the cut-out portion. The resonance frequency is adjusted by appropriately selecting the size or the position of the short-circuiting leg piece. Thus, the mounting board operates as an inverted-F antenna in which the power-feeding leg piece functions as a power feeding portion.