An adsorption-desorption material having a high carbon dioxide adsorption-desorption capability, a low pressure loss, a high thermal diffusion efficiency, and high resistance to repeated stresses, e.g., expansion and shrinkage, as well as an adsorption-desorption apparatus including the adsorption-desorption material, is provided. The adsorbent is composed of a three-dimensional network skeleton structure or a structure having three-dimensional network voids, the structure constructed by a compound having a carbon dioxide adsorption-desorption capability. The carbon dioxide adsorption-desorption apparatus is provided with this adsorbent.