In this article, the application of thermal analysis in the development of skin care cosmetics was explained based on three cases. The α-gel formed by fatty alcohols and surfactants is deeply involved in the physico-chemical properties and usability of cosmetic creams. The formation and physical properties of α-gel were verified by thermal analysis. By reducing the emulsion particle size in this cream formulation, the cream was transferred to a low viscosity water-like formulation. In order to keep this formulation stable, it was necessary to reduce the particle size of the emulsion until all the α-gel could be adsorbed from the aqueous phase to the emulsion interface. To prove this condition, quantitative analysis of the transition of α-gel to the interface by thermal analysis was useful. The extra-large size emulsion was stabilized by precipitation of fatty alcohol crystals around the emulsion particles. This structure was derived by finding the difference between the surface and internal state of the particles by thermal analysis. Thermal analysis clarified the physical properties and phenomena of the formulation and provided scientific support to establish it as a formulation technology in the development of a novel formulation.