A heartbeat detection device includes: a sensor data acquisition unit that acquires sensor data indicating an electrocardiographic waveform of a living body and outputs a sampling data sequence D(i) based on the sensor data; a first calculation unit that calculates a temporal difference value DY(i) of sampling data D(i) from the output sampling data sequence D(i) for each sampling time; a determination unit that determines a heartbeat time on the basis of a time at which a change in the calculated temporal difference value DY(i) exceeds a set threshold; a correction unit that corrects the heartbeat time by using a reference time; and a heart rate calculation unit that calculates a heart rate of the living body from the corrected heartbeat time.