To provide an adsorbing material having a heat accumulation function, in which a heat storage material including a heat storage capsule and an adsorbing material are mixed, and to provide a technique for allowing the heat storage capsule to be hardly broken by increasing the strength thereof and ensuring excellent adsorption-desorption performance so that the heat accumulation performance is not deteriorated even under such a condition that moisture exists and even under such a condition that an organic solvent exists.

A method for producing the adsorbing material 10 having the heat accumulation function, in which the heat storage material 4 including the heat storage capsule 3, that is obtained by encapsulating a phase change substance 1 for absorbing/radiating latent heat according to a temperature change in an outer shell, and the adsorbing material 5 are mixed, comprises the steps of: drying a dispersion liquid 3a including the heat storage capsule 3 to obtain powdery heat storage capsule 3b; and performing post-heat treatment for reheating the powdery heat storage capsule 3b within 110-140°C in order to again advance a polymerization reaction of a polymer compound 2 constituting the outer shell of the powdery heat storage capsule 3b.