A heartbeat measuring device has a measurement unit that measures a heart rate of a user, and an information storage unit that stores unique information regarding a heart rate unique to the user or information regarding a detected heartbeat of the user. A determination unit determines whether or not a heartbeat measurement state of the user is normal on the basis of the unique information or the information regarding a heartbeat stored in the information storage unit. An abnormality detection unit detects an abnormality corresponding to poor mounting of the heartbeat measuring device or interference due to external noise on the basis of a heart rate measured by the measurement unit. A notification unit performs a notification when the abnormality is detected by the abnormality detection unit. The notification unit changes information to be notified on the basis of a detection result by the abnormality detection unit.