PURPOSE: To shield a digital signal in a reception state and to measure pace in a nonreception state by supplying an AC signal to an electrode for electric field output only when a power supply to a receiver is not conducted.

CONSTITUTION: A shield plate 11 is connected always to the earth of a radio circuit 10. A transparent conductive film 12 for shielding a display surface, on the other hand, is connected to A', where an earth potential in a reception state or a pace measurement signal of 32Hz in a nonreception state are obtained through a circuit operating associatively with a power supply switch. Consequently, a digital part 5 is covered with a grounded conductor in the reception state to be shielded. The pace measurement signal of 32Hz is outputted to the surface of front glass 2 to measure pace in the non-reception state.