Disclosed is a grinding fluid supply device of a lens grinding apparatus. The grinding fluid supply device includes first grinding fluid supply means for supplying a grinding fluid in a tangent direction of a circular grinding wheel, which has a grinding surface formed on its circumferential surface, with an interval above a grinding surface and allows an upper portion and a rear side portion of the grinding surface to be covered with a curtain of the grinding fluid spaced from the grinding wheel when a processed lens is subjected to a grind processing with the grinding surface of the grinding wheel by rotatively driving the grinding wheel around an axis; and second grinding fluid supply means for insufflating the grinding fluid to the grinding surface.