Method for generating (releasing, emitting) or storing heat by reaction between, on the one hand, a solid and/or a first liquid and, on the other hand, a gas and/or a second liquid (ammonia, water, alcohol, ketone), wherein the reaction heat generated during the generation of heat or to be stored during the storage of heat is dissipated during the generation of heat or supplied during the storage of heat, wherein a1) on the one hand, a metered quantity of the solid and/or the first liquid is supplied to a reaction chamber and a2) on the other hand, a metered quantity of the gas and/or the second liquid or a metered quantity of heat is supplied to the reaction chamber, wherein in the reaction chamber a1) the solid and/or the first liquid and a2) during the generation of heat the gas and/or the second liquid or during the storage of heat the heat are brought into contact with one another and during the generation of heat the heat released is removed from the reaction chamber or during the storage of heat the gas and/or the second liquid released is removed from the reaction chamber, wherein the solid and/or the first liquid is an anhydrate during the generation of heat or a hydrate during the storage of heat, wherein the heat is generated or stored by reaction involving anhydrate during the generation of heat or hydrate during the storage of heat on the one hand and water and/or water vapor on the other hand, wherein a metered quantity of the anhydrate during the generation of heat or of the hydrate during the storage of heat is fed to the reaction chamber on the one hand and a metered quantity of water and/or water vapor during the generation of heat or a metered quantity of heat during the storage of heat is fed to the reaction chamber on the other hand, characterized in that an inner space of a container (K, K*) is partially filled with the anhydrate and/or the hydrate, and the container (K, K*) has a semipermeable wall region (WB1, WB2) which is impermeable to the anhydrate or hydrate contained therein and permeable to water or water vapor. a1) on the one hand, a metered quantity of the solid and/or the first liquid is supplied to a reaction chamber and a2) on the other hand, a metered quantity of the gas and/or the second liquid or a metered quantity of heat is supplied to the reaction chamber, wherein in the reaction chamber a1) the solid and/or the first liquid and a2) during the generation of heat the gas and/or the second liquid or during the storage of heat the heat are brought into contact with one another and during the generation of heat the heat released is removed from the reaction chamber or during the storage of heat the gas and/or the second liquid released is removed from the reaction chamber, wherein the solid and/or the first liquid is an anhydrate during the generation of heat or a hydrate during the storage of heat, wherein the heat is generated or stored by reaction involving anhydrate during the generation of heat or hydrate during the storage of heat on the one hand and water and/or water vapor on the other hand, wherein a metered quantity of the anhydrate during the generation of heat or of the hydrate during the storage of heat is fed to the reaction chamber on the one hand and a metered quantity of water and/or water vapor during the generation of heat or a metered quantity of heat during the storage of heat is fed to the reaction chamber on the other hand, characterized in that an inner space of a container (K, K*) is partially filled with the anhydrate and/or the hydrate, and the container (K, K*) has a semipermeable wall region (WB1, WB2) which is impermeable to the anhydrate or hydrate contained therein and permeable to water or water vapor.