PURPOSE: To raise a superconductive transition temperature as well as to make a fine pattern formable by heating an oxide containing a yttrium or lanthanum series element, barium and copper at a relatively low temperature of less than 900°C, and furthermore irradiating an exciting beam to it.

CONSTITUTION: An oxide containing at least one type element (a) in yttrium and lanthanum series elements, barium and copper (c) is heated at a temperature of less than 900°C, then an exciting beam is irradiated to it, thereby making the irradiated part into a superconductor. In this oxide as material, an atomic ratio of (a), (b) and (c) is not restricted in particular but such one that a:b:c=0.5W3:0.5W3:1.5W5 in usual time, especially a:b:c=1:2:3W4.5 is optimum. And, as for the exciting beam, short wavelength laser such as excimer laser is used. With this constitution, it shows superconductivity at high temperature at a liquid nitrogen temperature or so, while such an oxide whose part is superconductized in a fine pattern is securable.