PURPOSE: To manufacture the polyimide film, which is excellent in dimension stability and has few pin holes, by producing a film of a resin composition obtained by adding phosphoric ester and/or a salt of phosphoric ester and an amine to polyimide resin through a flowing and extending method.

CONSTITUTION: The resin composition containing a 0.001W5pts.wt. of the phosphoric ester shown in a formula II (R3, R4, R5 are H or a 6W18C alkyl group. Where one or two are H) and/or salt of the amine shown in a formula III (R6, R7, R8 are H, a hydroxyethyl group or a 1W4C alkyl group) and the phosphoric ester shown in the formula II to the 100pts.wt. polyimide resin with a not less than 85wt% repetition unit shown in a formula I (R1, R2 are tetravalent and bivalent aromatic organic groups) is flowed and extended on a metal supporter, and the film is manufactured. Accordingly, the polyimide film, which is excellent in dimension stability and which has few pin holes, can be produced at rapid manufacturing speed because the resin composition having excellent exfoliation property to the metal supporter is used.