An anomaly detection device is a device for detecting an anomaly in a mobile body and includes: a type determiner that determines a type of an anomaly detected; a type change determiner that determines whether or not a change has occurred between a type of an anomaly detected last time and a type of an anomaly detected this time; and an anomaly detection log transmitter that transmits an anomaly detection log related to the anomaly detected this time when the change has occurred, and does not transmit the anomaly detection log related to the anomaly detected this time when the change has not occurred.