To provide an improved adsorbent free of defects in conventional techniques and usable in PSA(pressure swing adsorption) or in a similar process.

There are provided a formed adsorbent material with an adsorbent solid phase and a vapor phase which ensures instantaneous transport of a gaseous component to the adsorbent solid phase. The material is such a material that the constants of transport dynamics of an adsorbable component in the vapor phase and solid phase satisfy a ratio of 0.1-10 when defined at 0.2 m/s gas discharge speed measured in terms of air at 1 bar and 20°C or a ratio of 0.1-10 when defined at 0.01 m/s gas discharge speed measured in terms of hydrogen at 30 bar and 40°C; Also provided is the use of the adsorbent for separating or refining a gaseous mixture such as air or hydrogen-base synthesis gas.