PURPOSE: To effectively insulate between circuit substrates by connecting an electric connection part between the substrates through a conductive material having adhesive properties in a laminated circuit substrate in which two circuit substrates are laminated in such a manner the circuit forming faces of the substrates face to each other, and adhering the nonelectric connection parts through a both-side adhesive sheet.

CONSTITUTION: As a conductive material 4 having adhesive properties for connecting electric connection parts between two circuit substrates, a hot metal type conductive paste or conductive sheet is employed. When volatile part can be easily volatilized, deposition dry type conductive paste is employed, and when the substrates can sufficiently transmit an ultraviolet ray and a paste film is thick, ultraviolet ray curable type conductive paste is employed. A both-side adhesive sheet 3 for adhering by insulating the two substrates is provided with adhesive layers 32 on both side faces of a base material 31 made of plastic film, paper, cloth, etc. Mold release paper is provided on the layer 32 as required. The mold release paper is isolated and adhered to the circuit forming face of the substrate at the time of using. The shape of the sheet 3 is suitably designed in response to the type of the conductive material 4 to be used for the electric connection part.