To enable a user to rapidly and orthogonally intersect and set a golf ball flight direction indicator and a ball setting position indicator with a less bulky implement by pivotally supporting the flight direction indicator and the ball setting position indicator and providing the pivotal supporting part thereof with an orthogonal setting mechanism.

The golf ball flight direction indicator 1 formed to a rectangular shape is formed longer than the setting position indicator 2. Both 1, 2 are adapted to be intersected orthogonally with each other and to be pivotally supported by the orthogonal setting mechanism 3. The shaft part 6a of a screw 6 housed into a recessed part 4 formed on the rear surface side of the flight direction indicator 1 in the state of receiving the repulsive force of a coil spring 5 is screwed to the setting position indicator 2. The flight direction indicator 1 is provided with setting holes 1b, 1c perpendicularly to the longitudinal direction and transverse direction on the near side of the shaft hole 1a of the flight direction indicator 1. The projection 2a formed on the rear surface of the setting position indicator 2 is socket-and-spigot fitted into these setting holes 1b, 1c, by which both indicators 1, 2 are intersected orthogonally and fixed.