PROBLEM TO BE SOLVED: To improve detection accuracy of a heartbeat signal for each individual by a heartbeat sensor.SOLUTION: A detection signal of a heartbeat sensor 21 and a detection signal of an inertial sensor 22 are received. Based on relationships between a heart rate obtained from the detection signal of the heartbeat sensor 21 while exercise strength obtained from the detection signal of the inertial sensor 22 is less than a threshold, and the exercise strength, a heart rate when the exercise strength is a threshold or more is estimated.SELECTED DRAWING: Figure 7【課題】心拍センサによる個人毎の心拍信号の検出精度を向上する。【解決手段】心拍センサ２１の検出信号と、慣性センサ２２の検出信号と、を受信し、慣性センサ２２の検出信号から得られる運動強度が閾値未満である間に心拍センサ２１の検出信号から得られる心拍数と前記運動強度との関係に基づいて、前記運動強度が閾値以上である場合の心拍数を推定する。【選択図】図７
