A device that differentiates a living body , the device comprising: at least one transmission antenna element that transmits a transmission signal to a predetermined range including the living body; N receivers (30A to 30H) that are arranged to surround a periphery of the predetermined range and configured to receive N reception signals, using respective reception antenna elements (31A to 31H) of the receivers during a first period, the N reception signals including a reflection signal resulting from the transmission signal reflected off the living body; a memory configured to store a teacher signal constituted of N reception signals obtained, during a second period, by the N receivers configured to receive in advance reception signals including a reflection signal resulting from a transmission signal that is transmitted from the at least one transmission antenna element to a subject living body and then reflected off the subject living body; a circuit configured to calculate a plurality of correlation coefficients between the teacher signal and each of the N reception signals by sliding correlation operation, calculate a cumulative probability distribution function with respect to the plurality of correlation coefficients, calculate a correlation coefficient, that is included in the plurality of correlation coefficients and has a cumulative percentage that indicates a first value in the cumulative distribution function, based on the cumulative probability distribution function and the cumulative percentage that indicates a first value, and determine that the living body and the subject living body are identical to each other when the correlation coefficient is included in a predetermined value range. at least one transmission antenna element that transmits a transmission signal to a predetermined range including the living body; N receivers (30A to 30H) that are arranged to surround a periphery of the predetermined range and configured to receive N reception signals, using respective reception antenna elements (31A to 31H) of the receivers during a first period, the N reception signals including a reflection signal resulting from the transmission signal reflected off the living body; a memory configured to store a teacher signal constituted of N reception signals obtained, during a second period, by the N receivers configured to receive in advance reception signals including a reflection signal resulting from a transmission signal that is transmitted from the at least one transmission antenna element to a subject living body and then reflected off the subject living body; a circuit configured to calculate a plurality of correlation coefficients between the teacher signal and each of the N reception signals by sliding correlation operation, calculate a cumulative probability distribution function with respect to the plurality of correlation coefficients, calculate a correlation coefficient, that is included in the plurality of correlation coefficients and has a cumulative percentage that indicates a first value in the cumulative distribution function, based on the cumulative probability distribution function and the cumulative percentage that indicates a first value, and determine that the living body and the subject living body are identical to each other when the correlation coefficient is included in a predetermined value range. <EOS>