PROBLEM TO BE SOLVED: To provide a vehicle eigen frequency detector capable of accurately detecting the eigen frequency of a vehicle, and to provide a center-of-gravity position measurement device capable of accurately measuring the height of the center of gravity of the vehicle using the vehicle eigen frequency detector.SOLUTION: The vehicle eigen frequency detector includes: a plurality of load cells 5, 6, 7, and 8 for detecting a load; a pedestal 3 that is supported by the load cells 5-8 and is mounted with a vehicle 4; a hydraulic cylinder 32 that oscillates the vehicle 4 on the pedestal 3 and stops the oscillation of the pedestal 3 oscillated together with the vehicle 4; and an MPU 40 that calculates the eigen frequency of the vehicle 4 on the basis of load signals of the load cells 5-8 and calculates the height of the center of gravity of the vehicle 4 on the basis of the eigen frequency.
