A processing device according to one aspect of the present invention includes a vibration detecting unit configured to detect a vibration of a vehicle, an orientation detecting unit configured to detect an orientation of the vehicle, a storing unit configured to store information indicating the orientation of the vehicle, a processing unit configured to set an orientation of a vehicle on a map of a navigation system based on the information indicating the orientation of the vehicle, and a power supply controlling unit configured to control power supplied to the orientation detecting unit and the storing unit based on a detection result of the vibration detecting unit and in response to an accessory power of the vehicle turned OFF.