TECHNOLOGY FOCUS - POLYMERS - Preferred Properties: The high polymer film has thickness of 20-300 microns, and satisfies the relation: (T4/T3)x100=85-100, where T3 is light transmittance of light having wavelength of 400 nm after heat processing at 250degreesC and T4 is light transmittance of light having wavelength of 400 nm after exposing to air for 2 hours. Preferred Film: The high polymer film further has transparent electrically conductive film or a gas barrier film, on at least one surface. The polymer film comprises polymer having a structural unit of formula (I).R1,R2=arbitrary aromatic groups;R3=OH, R5 or R12;R4=H, R6 or R27;R5=at least one group of formulae (1-4);R6=at least one group of formulae (5-8);R12=group of formula (9);andR27=group of formula (10).The structural unit equivalent to R3=OH and R4=R6 is set to A, and molar fraction of A is set to a, the structural unit equivalent to R3=R5, R4=R6 is set to B, and molar fraction of B is set to b, the structural unit equivalent to R3=OH and R4=H is set to C, and molar fraction of C is set to c, the structural unit equivalent to R3=R12, R4=H is set to D, and molar fraction of D is set to d, the structural unit equivalent to R3=R5, R4=H is set to E, and molar fraction of E is set to e, and the structural unit equivalent to R3=OH and R4=R27 is set to F, and molar fraction of F is set to f. x and y are defined by the following relationships: x=a/2+b, y=c/2+d, x=50-100, y=0-40 and a+b+c+d+e+f=100.R1,R2=same as defined above;andR7-R11=arbitrary aromatic groups or 1-10C aliphatic group.The z region contains at least one structural unit of formulae (VI-X).R13,R22=group having at least one 5-membered ring, 6-membered ring, or 7-membered ring;R14,R17,R20,R23,R25,R26=arbitrary aromatic groups;R15=halogen;R16=-CF3, -CCl3, -CBr3, -OH, -F, -Cl, -OCH3, where the structural unit having these groups in a molecule is optionally mixed;R18,R21=H, halogen or 1-3C hydrocarbon group;R19=-SO2-, -O-, -CH2-, -C(CF3)2-, or aromatic group containing one or more groups chosen from -SO2-, -O-, -CH2- and -C(CF3)2-;andR24=H or 1-3C hydrocarbon group.The molar fraction of the structural units of formulae (VI-X) is set to l-p, and satisfies the following relationships: 50 greater than l+m+n+oless than or equal to100, l-n=0-100, o=0-70, p=0-50, and l+m+n=100. EXAMPLE - 2-Chloro terephthalic acid chloride and 2,2'-bis(trifluoromethyl)-4,4'-diamino biphenyl were dissolved in dehydrated N-methyl-2-pyrrolidone, and polymerized for 2 hours, after ice cooling. The polymer product obtained was cooled again. Benzoyl chloride (1.1 mol%) was added and stirred for 1 hour. The neutralized with lithium carbonate (100 mol%), and aromatic polyamide solution containing polymer (10 wt.%) was obtained. The polyamide solution was flow-spread on a support, dried at 150degreesC for 15 minutes and solvent was evaporated. The polymer sheet formed was peeled from the support, washed with water for 15 minutes and heat processed for 1 minute at 230degreesC to obtain aromatic polyamide film with thickness of 50 microns. The film had high achromatism, without color change under high humidity.