Abstract: A high-frequency communication apparatus has a case containing a transmitter-receiver including circuit elements. A functional structure capable of confining radiation energy radiated by unnecessary radio wave source to prevent the radiation energy from interfering with the operations of the transmitter-receiver is formed on at least one of the walls of the case by forming a plurality of projections in regular arrangement by press working. The circuit elements of the transmitter-receiver are packed in the case to suppress the undesired electromagnetic coupling of internal and external electromagnetic waves with the circuit elements of the transmitter-receiver.