Af ter a kind mo ti va tion by Judit Si mon (Ed i tor-in-Chief of the Jour nal of Ther mal Anal y s is and Cal o ri m e t r y , Kluwe r Ac a dem ic Pub lis her) and ne go ti a tions with po- si ble con tri bu tors - lasting for m ore than one year - it was de cided to write a book about the ap pli ca tion of ther mal meth ods in bi ol ogy. Its aim was to be a guide how to per form ex per i ments and what kind of in for mation m ight be gained by them. We tried to col lect in for mation tha t could be achieved only dur ing a long per sonal pra- tice. In this way sci en tists from bi ol ogy and med i cine , e. g. , who are not so skilled in phys ics and math e mat ics may re al ize very soon the beauty and power of this tool at one hand. On the other hand, those sci en tists with better back ground in nat u ral sc- ences can be more sensitive to find out exciting biological problems.