in a method of forming a thick - film wiring on a substrate , photosensitive - electroconductive paste is filled into a pattern groove formed on the surface of a light - transmitting intaglio plate . the pattern groove corresponds to a desired thick - film wiring pattern . the photosensitive - electroconductive paste filled in the pattern groove are irradiated with light - rays from the front and back sides of the intaglio plate to cause the paste to harden until the overall peripheral surface of the electroconductive paste has a predetermined hardness . the electroconductive paste hardened in the pattern grooves of the intaglio plate is transferred to an intermediate piece . then , the electroconductive paste is transferred from the intermediate piece to a substrate . thereafter , the electroconductive paste is fired , whereby a thick - film wiring is formed on the substrate .