To provide a method for forming interconnection on a ceramic board without using a means of photolithography or sputtering, in which a conductive interconnection having a minute interconnection width of not more than 50 μm can be readily formed on a ceramic green sheet or a burned ceramic substrate, without contaminating the green sheet or the fired substrate.

A laser beam 2 is irradiated on a sheet material 1 made of a resin film or a metallic plate to form an opening 5 for forming an interconnection. This sheet material 1 is fixed by being either thermo-compressed for bonding to a ceramic green sheet 3 or by applying an adhesive thereto for bonding to a burned ceramics substrate. Then, the opening 5 of the fixed sheet material 1 is embedded with a conductive paste 4 and dried, followed by separating the sheet material 1 from the green sheet 3 or the substrate, and is finally subjected to firing.