To acquire a clear fatigue degree estimation result from the heartbeat fluctuation of a person by a simple method.SOLUTION: A fatigue degree estimation device includes: an R wave detection unit 3 for detecting an R wave from an electrocardiogram waveform of a target person； an R-R interval calculation unit 4 for calculating an R-R interval, which is a time interval between the R wave and the R wave immediately before it, which have been detected by the R wave detection unit 3； a difference calculation unit 5 for calculating a difference between the R-R interval away from each other by a certain heart rate； a ratio calculation unit 6 for calculating a ratio at which an absolute value of a difference between the R-R interval exceeds a certain value in a target period of the fatigue degree estimation, and a fatigue degree estimation unit 7 for estimating the fatigue degree of the target person on the basis of the calculated ratio.SELECTED DRAWING: Figure 6【課題】人の心拍変動から明確な疲労度推定結果を簡便な方法で得る。【解決手段】疲労度推定装置は、対象者の心電図波形からＲ波を検出するＲ波検出部３と、Ｒ波検出部３によって検出されたＲ波と１つ前のＲ波の時間間隔であるＲ－Ｒ間隔を算出するＲ－Ｒ間隔算出部４と、一定拍数離れたＲ－Ｒ間隔の差を算出する差分算出部５と、疲労度推定の対象期間においてＲ－Ｒ間隔の差の絶対値が一定値を超えた割合を算出する割合算出部６と、算出された割合に基づいて対象者の疲労度を推定する疲労度推定部７とを備える。【選択図】 図６
