The invention provides a hole structure through which is formed a deep through-hole having microscopic open ends, and also provides a method of fabricating the same. The hole structure of the invention contains a through-hole having a first open end and a second open end larger in size than the first open end, wherein the size, d, of the second open end is not smaller than 2 mu m and not larger than 50 mu m, and the through-hole has a depth t larger than d but not larger than 15d. The fabrication method of the invention comprises the steps of: forming an electrically conductive opaque layer in a prescribed pattern over a transparent substrate; forming a layer of insoluble photosensitive material on one side of the transparent substrate where the electrically conductive opaque layer is formed; applying exposure to the insoluble photosensitive material layer from the other side of the transparent substrate where the electrically conductive opaque layer is not formed; developing the insoluble photosensitive material and thereby forming a resist that matches the prescribed pattern; and forming the hole structure by electroplating on the one side where the resist has been formed. <IMAGE>