Abstract: The invention relates generally to high-temperature superconducting Josephson junction devices necessary in implementing an advanced a single flux quantum circuit for a digital electronic device using superconductors. More particularly, the invention relates to ramp-edge Josephson junction devices and methods for fabricating the same, using copper-series oxide super-conducting thin films. According to the present invention, the ramp-edge Josephson junction device comprises a substrate, a first electrode layer having a ramp-edge and a first insulating layer formed on the substrate sequentially, a transformation layer formed at the ramp-edge of the first electrode layer by illumination of excimer laser and by annealing process, and a second electrode layer and a second electrode layer and a second insulating layer formed on the first electrode layer including the transformation layer and the first insulating layer sequentially.