Gas sorption is a key technology for solving the global issues of energy and the environment that beset the world. From the end of the twentieth century, porous coordination polymers have been synthesized and studied as candidates for advanced adsorbents with a wide variety of applications. The regular nanospace of porous coordination polymers shows unique gas molecule capture and creates a new chemistry in the field of porous materials. In this article, we focus on the gas sorption properties of porous coordination polymers. Their uniqueness is illustrated using current representative results and discussed together with perspectives on the gas technology.