In 1925 a paper on kinetic analysis of data obtained with thermobalances for isothermal mass loss of some natural products for electrical insulation was published. This is the first theoretical and experimental approach to accelerated test of electrical insulating materials and also to kinetic analysis of thermal analysis data at isoconversional points. In succeeeding papers, change in chemical composition and kinetics under temperature change were dealt with. A historical review of these two topics is described in this review article, especially on the basic concept commonly induced for these two fields.