A maximum heart rate estimation method comprising: a first acquisition step (S1, S21, S31) of acquiring, by a heart rate acquisition unit, a heart rate of a target person who does exercise in an incremental load test that gradually increases exercise intensity; a second acquisition step of acquiring, by a feature amount acquisition unit, an electrocardiographic waveform of the target person who does the exercise in an incremental load test that gradually increases exercise intensity; a third acquisition step (S2, S22, S32) of acquiring, by the feature amount acquisition unit, a predetermined feature amount from the acquired electrocardiographic waveform, the predetermined feature amount being a QT interval, an RT interval, a height of a T wave, Root Mean Square of Successive Differences, an LF value, an HF value, an LF/HF ratio, Standard Deviation of the NN intervals, NN50, or pNN50; a step of obtaining, by an inflection point processing unit, a relationship between the predetermined feature amount and the heart rate, an extraction step (S4, S24, S34) of extracting, by the inflection point processing unit, an inflection point of the predetermined feature amount in the relationship between the predetermined feature amount and the heart rate, and obtaining a heart rate corresponding to the value of the feature amount at the inflection point, wherein the heart rate acquired in the first acquisition step (S1, S21, S31) corresponding to the value of the feature amount at the inflection point is set to correspond to an exercise intensity falling within a range of 35% to 45%; and an estimation step (S5, S25, S35) of estimating, by a maximum heart rate calculation unit, a maximum heart rate of the target person based on the relationship between the predetermined feature amount and the acquired heart rate, characterized in that the relationship between the feature amount acquired in the second acquisition step (S2, S22, S32) and the heart rate acquired in the first acquisition step (S1, S21, S31) contains the inflection point; in the estimation step, the maximum heart rate of the target person is estimated based on a heart rate corresponding to the value of the feature amount at the inflection point in a change of the predetermined feature amount with respect to the acquired heart rate, and wherein the estimation step includes a step of estimating the maximum heart rate using the equation: "maximum heart rate = resting heart rate + 100 × (heart rate at inflection point - resting heart rate)/exercise intensity at inflection point", where "resting heart rate" is a heart rate measured in advance at the time of rest, "heart rate at inflection point" is the heart rate corresponding to the value of the feature amount at the inflection point, and "exercise intensity at inflection point" is the preset value being within a range of 35% to 45%. a first acquisition step (S1, S21, S31) of acquiring, by a heart rate acquisition unit, a heart rate of a target person who does exercise in an incremental load test that gradually increases exercise intensity; a second acquisition step of acquiring, by a feature amount acquisition unit, an electrocardiographic waveform of the target person who does the exercise in an incremental load test that gradually increases exercise intensity; a third acquisition step (S2, S22, S32) of acquiring, by the feature amount acquisition unit, a predetermined feature amount from the acquired electrocardiographic waveform, the predetermined feature amount being a QT interval, an RT interval, a height of a T wave, Root Mean Square of Successive Differences, an LF value, an HF value, an LF/HF ratio, Standard Deviation of the NN intervals, NN50, or pNN50; a step of obtaining, by an inflection point processing unit, a relationship between the predetermined feature amount and the heart rate, an extraction step (S4, S24, S34) of extracting, by the inflection point processing unit, an inflection point of the predetermined feature amount in the relationship between the predetermined feature amount and the heart rate, and obtaining a heart rate corresponding to the value of the feature amount at the inflection point, wherein the heart rate acquired in the first acquisition step (S1, S21, S31) corresponding to the value of the feature amount at the inflection point is set to correspond to an exercise intensity falling within a range of 35% to 45%; and an estimation step (S5, S25, S35) of estimating, by a maximum heart rate calculation unit, a maximum heart rate of the target person based on the relationship between the predetermined feature amount and the acquired heart rate, characterized in that the relationship between the feature amount acquired in the second acquisition step (S2, S22, S32) and the heart rate acquired in the first acquisition step (S1, S21, S31) contains the inflection point; in the estimation step, the maximum heart rate of the target person is estimated based on a heart rate corresponding to the value of the feature amount at the inflection point in a change of the predetermined feature amount with respect to the acquired heart rate, and wherein the estimation step includes a step of estimating the maximum heart rate using the equation: "maximum heart rate = resting heart rate + 100 × (heart rate at inflection point - resting heart rate)/exercise intensity at inflection point", where "resting heart rate" is a heart rate measured in advance at the time of rest, "heart rate at inflection point" is the heart rate corresponding to the value of the feature amount at the inflection point, and "exercise intensity at inflection point" is the preset value being within a range of 35% to 45%.