To properly evaluate performance of such as tire dynamic characteristic at a tire designing stage.

This device is used when simulating and evaluating the tire dynamics characteristic. A tire model characteristic value forming part 11 determines natural frequency and vibration mode of a tire model as tire characteristic values based on the tire model showing a tire. A tire dynamics characteristic forming part 12 performs a mode synthesis of the tire characteristic value at a prescribed fixed point except the tire model to form a tire dynamics characteristic model. A dynamics characteristic evaluating part 14 decides interference amount of a load model applied to a tire dynamic characteristic model and the tire dynamic characteristic model to determine repulsion of the tire dynamic characteristic model based on the interference amount. According to the repulsion, the tire dynamic characteristic model is evaluated.