PURPOSE: To know whether the barycenter of a golf ball coincides with the spherical center or not easily and accurately by providing deviation indicating means which indicates a deviation with respect to a supporting member for a ball suspending frame which supports the ball suspending frame freely oscillatably.

CONSTITUTION: A ball suspending frame 2 is supported freely oscillatably with respect to a supporting member 3 for the suspending frame around its fulcrum as the pointed shaft 6 stuck to the top end of the ball suspending frame by facing downward by supporting by a bearing 7 provided to the member 3. A deviation indicating body 5 consists of a fine metallic wire-like material which is provided at the bottom end of a ball rest 4. The free end of said body directs an indicating part 9 consisting of a cruciform wire 9a provided to the member 3 and a concentrical circle 9b centering at the point of intersection of said wire. The indicating body indicates the tilting state of the frame 2 cooperatively with the part 9. When a golf ball B is placed on the ball rest while the body 5 directs the center of the part 9, and if the ball has a deviated barycenter, the frame tilts in the direction where the barycenter of the ball moves near the vertical line. Where the barycenter of the frame 2 balances with the barycenter of the ball, said frame comes to a standstill, and therefore the deviated barycenter of the ball is known.