PROBLEM TO BE SOLVED: To provide a biological information measurement circuit capable of measuring a subject's respiratory period on the basis of output of an acceleration sensor even at the time of running or jogging.SOLUTION: A biological information measurement circuit includes: a control unit that measures a period of single steps or duplication steps in a subject's walking or running on the basis of measurement data showing acceleration detected by an acceleration sensor, and sets the period as a unit period； a storage unit that stores measurement data showing acceleration in the front direction detected by the acceleration sensor at least in a unit period； and a calculation unit that calculates difference data showing a difference between measurement data showing acceleration in the front direction that is detected by the acceleration sensor and stored in the storage unit in a first unit period and measurement data showing acceleration in the front direction that is detected by the acceleration sensor in a second unit period differing from the first unit period, and calculates a respiration period on the basis of the difference data.SELECTED DRAWING: Figure 5
