Though mechanocardiogram is considered to have a high medical value, mechanocardiogram recording device is large in size and very expensive, obtained data lacks reliability, a measurement algorithm has not been settled, use of an apexcardiogram for diagnosis is not useful for diagnosis of the circulatory system, and there has been no measuring equipment capable of measuring pexcardiogram which contribute to determination of heal condition of a living body to be measured. For measurement of heartbeat of a living body, measuring device which allows simple measurement of apexcardiogram at bedside has been developed using a pressure sensor and/or wave sensor capable of measuring change in pressure at multiple portions adjacent to one another, and simple electronic circuit. Data processing algorithm for obtaining health information of a living body to be measured with high reliability from measured apexcardiogram and a biometric information measuring device having a new data processing algorithm on board have been developed to solve the problem.