To provide a method and an apparatus for simultaneously detecting the respiratory movements of a plurality of subjects inside a room without contact and without restraints.

Ultra wide band radio waves (UWB waves) are transmitted to the subject, a delay profile is obtained from reception signals by a preamplifier/detector, the delay profile is A/D converted, then observation is performed as the time variation of signal strength for each reflected wave in a signal processing part, and the respiration number or abnormal respiration of the subject is detected. Also, the respiration monitoring apparatus comprises an ultra wide band radio wave oscillator, an ultra wide band radio wave transmission/reception antenna, the preamplifier/detector for amplifying and detecting the reception signals and obtaining the delay protocol, an A/D converter for digitizing delay profile signals, and a signal processing part for outputting the time variation of signal strength for each reflected wave from the A/D converted delay profile.