Dry heat sterilisation is a method by which super-heat is applied to a device in order to sterilise it. Through this mechanism, the application of the sterilisation technology is only applicable to devices which can withstand temperature above 170°C. At higher temperatures, dry heat can additionally be used for depyrogenation, the inactivation of endotoxin. This chapter focuses on sterilisation, with covering the depyrogenation aspects more fully. This chapter examines the way by which dry heat destroys microorganisms and describes the additional mechanism for endotoxin inactivation. It then proceeds to describe the science behind dry heat, in terms of heat transfer, before discussing the main devices used for dry heat sterilisation. It chapter closes with an overview of the validation requirements.