PURPOSE: To lessen the number of required processes and shorten the manufacture time by exposing and developing applied dispersed liquid.

CONSTITUTION: In the manufacture of a film substrate 1, to begin with, copper powder dispersed liquid 3, wherein copper fine powder 5 is dispersed beforehand in polyimide solution including polyimide being photosensitive resin, is applied on the surface of a polyimide film, where a through hole 2 is bored, and inside its through hole, as a dispersed liquid application process. Subsequently, specified circuit mask patterns are installed on the surface of the copper powder dispersed liquid 3 being applied on both sides, and exposure and development processing is conducted, whereby the copper dispersed liquid 3 at the exposed section is removed, and it becomes an etching groove 7, and a circuit film 5 is developed. Accordingly, it follows that the dispersed liquid application process doubles as a conductive metallic film formation process in a public conventional method and a photo resist application process for etching a circuit. Accordingly, the number of required processes decreases.