A gas separation method is provided in which, when separating a first
component and a second component from a mixed gas containing a plurality
of components by using a pressure swing adsorption method, these
components can be efficiently recovered and cost reduction can be
achieved. Between an adsorption step and a regeneration process step,
which use a first adsorption column containing a first adsorbent on which
the first component is less readily adsorbable and the second component
is absorbable, and a second adsorption column containing a second
adsorbent on which the first component is readily adsorbable and the
second component is less readily adsorbable, an equalization
depressurization step and an equalization pressurization process step, in
which the pressure of the first and second adsorption columns is
equalized, is carried out.