The present invention is one that reproduces behavior close to an actual run of a vehicle in a test using a loading device, and is a specimen test apparatus that tests a specimen that is a vehicle or a part of a vehicle. The vehicle test apparatus includes: a loading device that is connected to a rotating shaft of the specimen and gives running resistance to the rotating shaft; a storage part that stores tire diameter data indicating the relationship between a running state of the specimen and a tire diameter; and a control part that, from the tire diameter data, calculates a tire diameter corresponding to a running state of the specimen, and controls the loading device with use of running resistance obtained from the calculated tire diameter.