abstract |
A porous polyimide film has an acid value within a range of 7 mgKOH/g to 20 mgKOH/g determined by acid-base titration, contains a metal group including alkali metals excluding Li, an alkaline earth metals, and silicon at a total content of 100 ppm or less relative to the porous polyimide film, and has a moisture absorption ratio of 0.5% or less. |