The present invention is a humidity conditioner having a configuration in which one or more water-soluble polymers are introduced into a three-dimensional framework that is formed by one or more crosslinked water-absorbing polymers. Here, for the water-absorbing polymers, either polyacrylate salt or one or more polyacrylate salt-polyvinyl alcohol copolymers can be used. For the water-soluble polymers, one or both of polyvinyl alcohol and polyisopropylacrylamide can be used.