The well-established electrolysers belong either to the low temperature class, working at temperatures up to ca. 100 °C (the alkaline electrolyser and the PEM electrolyser) or to the high temperature class, operating at temperatures of ca. 600 °C and above (the solid oxide electrolyser). Intermediate temperature refers to the wide temperature gap between these temperatures. In this chapter, some overarching reflections on the implications of operating electrolysers at intermediate temperatures are followed by three examples of such technologies. The examples chosen are an alkaline electrolyser working at 200–250 °C, a PEM electrolyser working at 120–130 °C and a system based on solid or molten phosphates aiming at CO₂ reduction at 200–350 °C.