PURPOSE: To produce a stabilized temperature environment shielded sufficiently from external electromagnetic noise at low cost in the temperature inspection of a receiver.

CONSTITUTION: An encoder 19 and a high frequency signal generator 20 are disposed on the outside of an electromagnetic shielding box 12 having a plurality of closable holes 13 or a plurality of holes 13 each fitted with a conductive pipe 14. A receiver 11 is placed in the box 12 and a transmitting receiver 15 is fixed to the receiver 11. A temperature control means 21 disposed on the outside of the box 12 controls the inner temperature of the box 12. The high frequency signal generator 20 outputs a high frequency signal based on a signal received from the encoder 19 and transmits the high frequency signal from the transmitting antenna 15. The receiver 11 receives the radio wave and generates a response sound. An inspector listens the response sound being transmitted to the outside through the plurality of holes 13 in the box 12 or the conductive pipes 14 and then makes a decision. The noise generated from the encoder 19 and the high frequency generator 20 and the external noise are shielded by the electromagnetic noise shielding box 12 and the receiver 11 is not affected thereby.