Fluorine-containing polymer and method of producing same

A fluorine-containing polymer, having a fluorine content of 50% by mass or more, a degree of unsaturation of 0.1 mEq/g or more, and a glass transition temperature of −20° C. or higher,

• wherein:
• a relationship between a maximum value E*1 of a complex elastic modulus in a range of from −50° C. to (glass transition temperature −10° C.) and a minimum value E*2 of the complex elastic modulus in a range of from (glass transition temperature +10° C.) to 250° C. satisfies the following inequality:
• E*2/E*1≤0.01,
• the fluorine-containing polymer is a polymer of a compound of Formula (1) or a copolymer of the compound of Formula (1) and a compound having a reactive carbon-carbon double bond and that is different from the compound of Formula (1);
• where Y7 represents a divalent organic group having at least one fluorine atom, each of R1 to R6 independently represents a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or an organic group having 1 to 5 carbon atoms, each of R1 and R3, R4 and R5, R2 and Y7, and R6 and Y7 may be independently linked to each other to form a ring structure, and
• a fluorine content of the compound of Formula (1) is 20% by mass or more.