NOVELTY - An asymmetrical hollow fiber gas separation membrane comprises soluble aromatic polyimide.    USE - An asymmetrical hollow fiber gas separation membrane used for selective separation-and-recovery method of hydrogen gas (claimed).    ADVANTAGE - The separation membrane has high gas-separation performance.    DETAILED DESCRIPTION - An asymmetrical hollow fiber gas separation membrane comprises soluble aromatic polyimide which consists of repeating unit of formula (1).    B = 20-60 mol% of tetravalent unit B1 with diphenyl hexafluoro propane structure of formula (2), or 80-40 mol% of tetravalent unit B2 with biphenyl structure of formula (3);    A = 95-50 mol% of bivalent unit A1 of formula (4) and/or bivalent unit A2 of formula (5), or 5-50 mol% of bivalent unit A3 of formula (6);    R, R' = H or organic group;    n = 0-2; and    X = -CH2- or -CO-.    INDEPENDENT CLAIMS are included for:    (1) a supply method of high pressure mixed gas involving supplying gas with pressure of 1 MPaG to asymmetrical hollow fiber gas separation, and performing gas separation;    (2) a selective separation-and-recovery method of hydrogen gas from mixed gas containing hydrogen gas, involving using asymmetrical hollow fiber gas separation membrane; and    (3) a manufacturing method of asymmetrical hollow fiber separation membrane involving using aromatic polyimide solution whose viscosity is 150000 poises in 100 degrees C. The aromatic polyimide solution contains aromatic polyimide, and organic polar solvent which consists of phenols, catechol, halogenated phenol or amides. The aromatic polyimide consists of tetracarboxylic acid component, and diamine component. The tetracarboxylic acid component contains 10-60 mol% of 4,4'-(hexafluoro isopropylidene) diphthalic acid, its dianhydride or its esterified substance, and 90-40 mol% of biphenyl tetracarboxylic acids. The diamine component contains 95-50 mol% of aromatic diamine of formula (8) and/or aromatic diamine of formula (9), and 5-50 mol% of aromatic diamine of formula (12).    R, R'=H or organic group;    n = 0-2; and    X = -CH2- or -CO-.