The operation principle of the Mettler-Toledo RCl reaction calorimeter and its possible application to investigations of the processes carried out in the chemical industry are presented. There are given the following applications of the presented equipment: to investigation of the chemical reaction kinetics, to developing the scaling-up procedures for the processes carried out in batch and semi-bath reactors as well as to studying the safety of chemical reactors. The results of experiments performed to investigate the reaction kinetics and reactor safety are presented and discussed.