TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Substance: The phase transition substance is barium hydroxide octa hydrate and/or strontium hydroxide octa hydrate. Preferred Agent: The non water-soluble intermediate agent is Freon intermediate agent. The capsulation agent is vinyl compound. The dispersion agent is water-soluble dispersion agent. Preferred Method: The phase transition substance is dispersed and dispersed in non water-soluble intermediate agent heated more than the melting point, and an emulsion is obtained. The emulsion is cooled below its melting point, and liquid phase transition substance is solidified. The solid-state phase transition substance is dispersed in non water-soluble intermediate agent and suspension liquid is produced. A polymerization initiator, monomer of capsulation agent and the suspension liquid are mixed, and heat absorption emission capsule is produced. EXAMPLE - NACALAI TESQUE (RTM: barium hydroxide octahydrate having melting point of 78degreesC) (phase transition substance) (in g) (104) was dissolved in perfluoro carbon (5 ml) heated to 80degreesC, and heated to 90degreesC. Ftergent 150 (RTM: fluorine-type emulsifier) (2.5) was added, emulsified at 100 MPa at 85degreesC for 10 minutes and emulsion was obtained. The emulsion was cooled to 60degreesC, and liquid barium hydroxide octa hydrate was solidified. The solid-state barium hydroxide octa hydrate having volume average particle diameter of 0.3 microns was dispersed in perfluoro carbon, and suspension liquid was produced. Styrene monomer (capsulation agent) (22.6) and divinyl benzene (1.13) were added to the suspension liquid (500 ml), and heat-stirred at 60degreesC for 10 minutes. Then, ACVV (RTM: 4,4-azobis-4-cyano valeric acid) (polymerization initiator) (0.47) was added, and polymerized at 60degreesC for 12 hours, capsule wall was formed, and heat absorption-emission capsule was obtained. The heat absorption-emission capsule was added to water (water-soluble dispersion medium), water and perfluoro carbon were filtered and removed, and heat absorption-emission capsule dispersion liquid was obtained. The dispersion liquid had large thermal capacity and high heat absorption-emission capability.