PURPOSE: To correct the output level to a prescribed level in the case that the output level is much changed and normal correction is impossible by preliminarily holding change data, which changes control data which keeps the normal output level of a base band part, in a ROM newly provided in a control part.

CONSTITUTION: If a comparison circuit 1111 of an automatic correction circuit 111 detects the excess of a control voltage Vcont of a variable attenuator 1 over a prescribed threshold 1112 to output a detection signal c and it is judged by this signal C that normal automatic control of the transmission output level in the variable attenuator 1 is impossible, a set change signal generating circuit 1113 of the automatic correction circuit 111 generates a set change signal (d) and reports it to a control circuit 102 of a control part 10. The control circuit 102 reads out preliminarily set change data from a ROM 101 and sends set change data to a base band part (a) to raise or reduce the output level of the base band part (a) Thus, the transmission output level of the output of a radio transmission part (f) is controlled to a prescribed value.