The design of a novel differential scanning calorimeter (DSC) sample crucible that allows for the analysis of liquid and solid materials (the solids can also be wetted with a liquid) at high temperatures is described. The sample to be analyzed is placed within a thin walled stainless steel tube, which is then sealed by tungsten inert gas (TIG) welding. The stainless steel tube is 8.8mm (0.35in.) long, has an outer diameter of 3.14mm (0.125in.) and a wall thickness of 0.015mm (0.006in.). Placing the flattened end of the tube in the jaws of a large copper block (heat sink) allows for the sealing of the tube by TIG welding without heating the sample excessively. The utility of the sample crucible is demonstrated by a study of the kinetics of the thermal decomposition of di-t-butyl peroxide (DTBP), where an activation energy of 140kJmol−1 and a frequency factor of 5.30×1013 s−1 was obtained.