To provide a method of easily and accurately measuring body sound for a long time by paying attention to the body sound generated in connection with heartbeat or pulmonary respiration in a human body.

As means for solving the problem, a long time body condition monitoring system and device to collect body sound generated in connection with heartbeat or pulmonary respiration by a sound catcher, record it in a memory for a long time, and analyze the record with a computer is provided. The sound catcher is formed to have a cap shape, for instance, to be mounted as a microphone cap on a small condenser microphone. The sound catcher is worn on an upper arm, the vicinity of the heart or the vicinity of the carotid artery of the throat so as to be in contact with them while maintaining air tightness and the body sound caught thereby can be amplified and recorded in a memory. The recorded data are analyzed and digitized by a program and provided for diagnosis. Measurement of body temperature is carried out by attaching a commercially available chip shape temperature data logger to the armpit with a pressure-sensitive tape so as to be tightly in contact with the body.