Fluoropolymer membranes

The technical problem to be solved by the present invention is to provide a fluorine-containing polymer film. This problem is solved by a method in which the fluorine-containing polymer film has a thermal shrinkage rate of 0.4% or less after being heated at 90 DEG C for one hour and a relative dielectric constant of 3-50 at 25 DEG C and 1000 Hz, or the fluorine-containing polymer film has a crystallinity of 50% or more and an elongation at break of 400% or more. 本发明所要解决的技术问题在于提供一种含氟聚合物膜。该技术问题通过以下的方式解决：上述含氟聚合物膜以90℃加热1小时后的热收缩率为0.4％以下，25℃且1000Hz时的相对介电常数在3～50的范围内，或者上述含氟聚合物膜的结晶度为50％以上，断裂伸长率为400％以上。