Abstract: A method of manufacturing a superconducting wire is carried out by first preparing a material being composed of Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7. This material is melted in a platinum crucible. A melt thus obtained is drawn out from a hole provided on the bottom wall of the crucible to be linearly discharged. The linearly discharged melt is cooled and solidified. A cooling/solidifying space for such a step is set at a temperature less by about 10.degree. C. than the solidifying point of the material, and a slow-cooling zone is provided next to the cooling/solidifying space. This slow-cooling zone is provided to be at a relatively high temperature in a portion closer to the hole while having a temperature gradient along a direction for linearly discharging the melt. A superconducting wire being composed of Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7 is obtained. This superconducting wire superconducts at 85K.

Abstract: A ceramic type superconductive layer (2) is formed on the outer peripheral surface of an optical fiber (1), and a stabilizing layer (3) is formed so that it contacts the outer peripheral surface of the superconductive layer (3). The diameter of the optical fiber is, for example, not more tha 100 .mu.m. The superconductive layer may be formed with a spirally extending groove (7) which divides the superconductive layer.