Gas separation membranes, poly (benzoxazole - imide) has a gas separation layer containing the compound, poly (benzoxazole - imide) compound, a structural unit represented by (A) the general formula (I), the general and a structural unit represented by the formula (II), poly - represented by (benzoxazole-imide) in the compound, a molar amount m of the structural unit represented by formula (I), the general formula (II) and the molar amount n of the structural unit that satisfies the equation 1, or (B) and the general formula a structural unit represented by the formula (I), a structural unit represented by the formula (II), the general formula (III) and a structural unit in represented by poly (benzoxazole - imide) in the compound, a molar amount m of the structural unit represented by the general formula (I), the structural unit represented by the general formula (II) a molar amount n, the molar amount q of the structural unit represented by the general formula (III) satisfies the equation 2, moth Separation membrane.
Equation 1: 0.25 ≦ m / n ≦ 9.00 (0 <n)
Equation 2: 0.25 ≦ m / (n + q) ≦ 9.00 (0 <n, 0 <q)

Wherein, X and Y represents a single bond or a specific divalent linking group. L represents a specific divalent linking group containing a phenylene group. R represents a particular group. Gas separation modules and gas separation method using the above gas separation membrane. Gas separation apparatus comprises the gas separation module.