The invention relates to a device and to a method for the implementation thereof for measuring the dew point temperature of a gaseous element, alone or in a mixture, which can have a low calorific capacity and/or an aggressive chemical character like sulfur, circulating for example in a pipe, working at a range of temperatures varying from around 100 to 400°C and providing an optimized precision in the measure due to an optimized signal-to-noise ratio. For this purpose, the device includes in particular a calorimetric unit (2), two thermometric means (3, 4) and a measuring surface (8), each of the latter (3, 4, 8) being in direct thermal contact with the calorimetric unit and the gaseous element. Each thermometric means is capable of generating a signal representative of the thermal effect associated with the condensation and/or the evaporation of the gaseous element on said surface (8).