A fluorocopolymer and film thereof exhibiting excellent transparency and mechanical strength at ambient and elevated temperatures, wherein the fluorocopolymer includes polymerized units based on ethylene (E), tetrafluoroethylene (TFE), hexafluoropropylene (HFP) and perfluoro(alkyl vinyl ether) (PFAV), wherein the molar ratio of polymerized units based on E/TFE is from 10/90 to 60/40, the content of polymerized units based on HFP is from 0.2 to 0.9 mol % based on the total number of polymerized units, and the content of polymerized units based on PFAV is from 0.1 to 1.0 mol % based on the total number of polymerized units.