PURPOSE: To provide a device for detecting a parked vehicle capable of accurately detecting the parked position of a vehicle with low power consumption.

CONSTITUTION: The position of the vehicle is detected by signals from an antenna 1a for GPS at all times and when a driver pulls out a key 2 for the vehicle from the key cylinder of the vehicle, a detected vehicle position is recorded at a data processing part 1b as the parked position. When the driver moves while carrying this detection device in the case of parking the vehicle and going away, the present position is detected through the GPS at all times, the positional relation of the present position and the parked position is calculated at the data processing part 1b and is displayed at a display part 1c.