A method for separating and recovering oxygen-rich air from the air,
comprising, using a gas separation membrane module where a laminate
consisting of a permeate-side spacer for forming a permeate gas channel
communicated with a hollow section in a core tube for collecting and
discharging a permeate gas and two flat-film gas separation membranes
sandwiching the spacer and a feed-side spacer for forming a feed gas
channel are spirally wound around the core tube such that the laminate
and the feed-side spacer are alternately superimposed, vacuuming the
hollow section of the core tube to 95 kPaA (absolute pressure) or less by
vacuuming means while feeding the air into the feed gas channel by air
feed means such that a maximum feed-air flow rate and a maximum static
pressure divided by an effective membrane area of the gas separation
membrane are 100 m.sup.3/minm.sup.2 or less and 4000 Pa/m.sup.2 or less,
respectively, to separate and recover oxygen-rich air from the hollow
section of the core tube. Oxygen-rich air can be separated and recovered
from the air by this method with high separation efficiency.