Conductive substrate comprising a metal fine particle sintered film

Provided is a conductive substrate which is prepared by forming a pattern-shaped metal fine particle sintered film such as a copper wiring and the like on a base material of polyimide and the like and which has a high adhesive property with the base material and is provided with an excellent conductivity. The conductive substrate of the present invention is prepared by printing a coating liquid containing metal or metal oxide fine particles on a base material to form a print layer and subjecting the above print layer to sintering treatment to form a metal fine particle sintered film, wherein a crystallite diameter in the metal fine particle sintered film which is measured by X ray diffraction is 25 nm or more, and a cross section of the metal fine particle sintered film has a void rate of 1% or less.