PURPOSE: To make an opening area of a cup changeable so that a golf ball is cupped in moderate probability, in a golf game course or a driving range.

CONSTITUTION: By operating a selection switch, an electrically-driven motor 33 is rotated, the rotation of the motor 33 is transferred to a rotary shaft 31 through a belt 32 and the shaft 31 is rotated. By the rotation of this rotary shaft 31, a bottom face plate 27b formed integrally with a third plate 27 formed by attaching fixedly a nut 28 is allowed to ascend and descend. In connection with the ascent and the descent of this bottom face plate 27b, a second plate 24 is allowed to ascend and descend by an action of a projection 27c and a tension spring 25. Accordingly, an opening area of a golf cup is switched to the diameters determined by the inside diameters of a first - a third plates 22, 24 and 27, that is, three stages.