A device that differentiates a living body includes at least one transmission antenna element that transmits a transmission signal to a predetermined range including the living body, N receivers that are arranged to surround a periphery of the predetermined range and each receive N reception signals using respective reception antenna elements of the receivers during a predetermined period, the N reception signals including a reflection signal resulting from the transmission signal reflected off the living body, memory that stores a teacher signal, a circuit that calculates a plurality of correlation coefficients according to the teacher signal and the N reception signals received by the N receivers and determines that the living body and the subject living body are identical to each other when a predetermined correlation coefficient included in the plurality of correlation coefficients is included in a predetermined value range.
