NOVELTY - A liquid fluoro polymer composition comprises a fluoro polymer fluid which contains a liquid medium and a crosslinkable fluoro polymer. The fluoro polymer fluid is liquid fluoro polymer dispersion (AD) having a liquid dispersion medium dispersed with cross-linkable fluoro polymer particles having an acid/acid salt group or organic group, or fluoro polymer solution (AS) having specific solvent dissolved with crosslinkable fluoro polymer.    USE - For manufacture of fluorine group cross-linked component such as electrode component or electrolyte film for solid polymer electrolyte fuel cells (claimed).    ADVANTAGE - The fluorine group cross-linked component has excellent durability, mechanical characteristics and small dimensional change rate, and is manufactured efficiently.    DETAILED DESCRIPTION - A liquid fluoro polymer composition comprises a fluoro polymer fluid which contains a liquid medium and a crosslinkable fluoro polymer. The fluoro polymer fluid is liquid fluoro polymer dispersion (AD) containing a liquid dispersion medium dispersed with particles of cross-linkable fluoro polymer having an acid/acid salt group or organic group, which upon hydrolysis converted to carboxy, or fluoro polymer solution (AS) comprising fluorochemical solvent or alcohol/water mixed solvent dissolved with crosslinkable fluoro polymer having an acid/acid salt group or its precursor, or organic group which upon hydrolysis converted to carboxy. The acid/acid salt group is sulfo, carboxy, -SO2-NR2R3, -SO3-NR4R5R6R7, -SO3M11/_L, -COONR8R9R10R11, or -COOM21/_L. The precursor is -SO2F or -SO2NR22R23.    R2=H or M51/_L;    R3=alkyl or sulfonyl-containing group;    R4-R11=H or alkyl;    M1,M2,M5=L-valent metal chosen from group 1, group 2, group 4, group 8, group 11, group 12 or group 13 element of periodic table;and    R22,R23=alkyl group.    An INDEPENDENT CLAIM is included for manufacture of fluorine group crosslinked component, which involves applying the liquid fluoro polymer composition on a base material or a porous material, removing the fluid medium and performing crosslinking process.