A radio communication apparatus, comprising: a receiver configured to receive a radio signal of which communication medium is radio waves and to demodulate and decode a transmission frame contained in the radio signal; a controller configured to obtain data from the transmission frame demodulated and decoded by the receiver to process the data; and a power supply configured to energize the receiver and the controller, wherein the controller is configured to: receive a synchronizing signal from a base station at fixed intervals; after elapse of a prescribed time from a time point the synchronizing signal has been received, count passage of an intermittent reception interval with a constant period to activate the receiver whenever passage of each intermittent reception interval has finished being counted; and stop the receiver immediately to shift the receiver to a stand-by-state, when a receiving signal strength indication signal from the receiver is below a threshold, keep the receiver operating when the receiving signal strength indication signal from the receiver is equal to or greater than the threshold wherein the receiver captures a preamble of the radio signal, and reactivate the receiver after elapse of a prescribed stand-by time from a time point the receiving signal strength indication signal of the receiver is below the threshold, the stand-by time being set to be equal to or less than a time until the radio signal is retransmitted. a receiver configured to receive a radio signal of which communication medium is radio waves and to demodulate and decode a transmission frame contained in the radio signal; a controller configured to obtain data from the transmission frame demodulated and decoded by the receiver to process the data; and a power supply configured to energize the receiver and the controller, wherein the controller is configured to: receive a synchronizing signal from a base station at fixed intervals; after elapse of a prescribed time from a time point the synchronizing signal has been received, count passage of an intermittent reception interval with a constant period to activate the receiver whenever passage of each intermittent reception interval has finished being counted; and stop the receiver immediately to shift the receiver to a stand-by-state, receive a synchronizing signal from a base station at fixed intervals; after elapse of a prescribed time from a time point the synchronizing signal has been received, count passage of an intermittent reception interval with a constant period to activate the receiver whenever passage of each intermittent reception interval has finished being counted; and stop the receiver immediately to shift the receiver to a stand-by-state, when a receiving signal strength indication signal from the receiver is below a threshold, keep the receiver operating when the receiving signal strength indication signal from the receiver is equal to or greater than the threshold wherein the receiver captures a preamble of the radio signal, and reactivate the receiver after elapse of a prescribed stand-by time from a time point the receiving signal strength indication signal of the receiver is below the threshold, the stand-by time being set to be equal to or less than a time until the radio signal is retransmitted.