The present invention relates to an automatic golf ball supply device, being an automatic golf ball supply device which automatically supplies golf balls to a position where the golf balls will be hit with a golf club by the user, which comprises: a frame on the upper part of which is formed a golf ball withdrawal hole; an ascending and descending mount which ascends and descends by means of a motor, and on the upper surface of which is provided a tee member where a golf ball rests, and which is provided so as to ascend and descend freely in the withdrawal hole direction following a guide provided in the frame; and a golf ball conveying loader which conveys golf balls towards the tee member of the ascending and descending mount as the outer circumferential surface rotates and makes contact with the golf balls inside a golf-ball-waiting chamber in such a way as to be able to push each golf ball and to rest the same on the tee member. Consequently, there are advantages in that the height of the frame can be minimized and there are great savings on the weight, volume and installation space of the product, and in that it is possible to reduce the number of parts and hence increase productivity and economize on production costs, and to minimize loss of motive force and so maximize the force with which the golf balls are conveyed.