To provide an unmanned parking device in which a leaving protective member 26 is positioned to its leaving prohibiting position at a specified time after a vehicle enters.

This unmanned parking device comprises a detector 18 to detect a vehicle entering a parking lot, and the leaving prohibiting member 26 to be raised to the leaving prohibiting position based on detection of entering of the vehicle into each parking lot by the detector 18. The leaving prohibiting member 26 is controlled to reach the leaving prohibiting position at a specified time of 30 sec. or more for definition of entering after detection of the entering of the vehicle by the detector 18. The entering defining time is, favorably, about 2 min. or more. When the leaving prohibiting member 26 reaches the leaving prohibiting position, counting parking time can be started.