PURPOSE: To obtain a board for a flexible printed circuit board having excellent heat resistance, chemicals resistance, no curl, no twist, dimensional stability at a high temperature, excellent electric characteristics by altering composition of polyimide resin having a special structure and forming a multilayer of the composition.

CONSTITUTION: A polyimide resin layer laminated directly on a conductor is formed of a polyimide resin layer of at least two different compositions. At least two layers of them are a polyimide resin layer A containing 50-100wt.% of constituent unit represented by a formula I and a polyimide resin layer B containing 20-90wt.% of the unit in such a manner that the layer A contains at least 10wt.% more than the unit of the layer B, and the layer A is provided closer to the conductor than the layer B. In the formula I, R1-R4 are group selected from hydrogen, halogen, lower alkyl group, lower alkoxy group, nitro group or nitrile group.