A radio transmitter includes a CPU, functioning to allow the radio signal to be transmitted in event of a decision result that the radio signal transmission should be permitted but, in event of a decision result that the radio signal transmission should not be permitted, functions to allow the radio signal to be stopped and to instruct the alarm output section to output an abnormal alarm; a distributor, functioning to distribute a radio signal outputted from the radio transmitter to the outside; a transmitter; a spectral analysis, functioning to perform a frequency analysis of the radio signal according to the standard information; a power comparator section, to decide whether or not a transmission of the radio signal should be permitted by comparing the result of the frequency analysis with the standard information; and an alarm output section.