A sleep measurer comprises frequency analyzing means for frequency-analyzing a brain wave detected from an organism and thereby extracting each frequency component of the d wave, the a wave, the s wave, and the ß wave and sleeping state judging means for judging the sleeping state for each predetermined time block on the basis of the content and the rate of content of each frequency component of the d wave, the a wave, the s wave, and the ß wave. A sleeping state judging method comprises a step of frequency-analyzing a brain wave detected from an organism and thereby extracting each frequency component of the d wave, the a wave, the s wave, and the ß wave and a step of judging the sleeping state for each predetermined time block on the basis of the content and the rate of content of each frequency component of the d wave, the a wave, the s wave, and the ß wave.
SLEEP MEASURER AND SLEEPING STATE JUDGING METHOD