An atrial fibrillation analyzer includes: an acquisition unit that acquires a waveform signal indicating a temporal change of a pulse wave or an electrocardiogram； an RR interval calculation unit that calculates a parameter corresponding to an average RR interval for each frame on the basis of a spectrum of each frame obtained by frequency analysis of the acquired waveform signal, and calculates an RR waveform signal indicating a temporal change of the parameter； a power calculation unit that calculates a temporal change of power of a predetermined frequency band in a frequency spectrum of the RR waveform signal； a variation coefficient calculation unit that calculates a variation coefficient of the average RR interval； an analysis unit that analyzes presence of atrial fibrillation on the basis of a set of the power and the variation coefficient； and a measurement unit that measures an amount of activity of a user.
