To solve the problem of increasing installation cost, for requiring repavement by excavating the ground surface of a parking space for embedding a vehicle detecting sensor in a conventional structure, in a car stop post device arranged on the ground surface of a parking garage.

The vehicle detecting sensor is built and arranged in a casing of the car post device. The occurrence of a detection error by using a small sensor, is prevented by incorporating a plurality of sensors at a prescribed interval. The sensor can be protected from wind and rain and impact, without hindering detecting accuracy of the sensor, by adopting a structure for arranging a geomagnetism sensor inside a magnetically permeable window arranged on an upper surface of the car stop post device, and the degree of freedom of a sensor arranging position can also be enhanced.