A portable electronic device is provided that is capable of reducing the degradation in the characteristic of an antenna caused by the orientation direction of the antenna being fixed. The device includes a circuit board disposed in the vicinity of an antenna, a conductive switch terminal that is provided to the circuit board and detects an operation to an operation unit, a reference potential part provided to the circuit board to be opposite to the switch terminal, a conductive part provided to the circuit board to be opposite to the antenna, and a switch unit capable of switching whether the reference potential part and the conductive part are electrically connected.