Abstract: The invention relates to a temperature-gradient incubator for studying temperature dependent phenomena, such as temperature ranges for the growth of microbes, comprising a temperature-gradient plate (10) serving as a reaction substrate and heat transfer elements (17 and 18) extending along the opposite edges of the temperature-gradient plate (10) for the heating and cooling of the edges of the temperature-gradient plate (10). Each heat transfer element (17 or 18) is provided with two passages for the circulation of a heating and/or cooling medium. Gable elements (9, 16) connect the passages to each other. The gable elements (9, 16) and pipe joint elements (6, 13) are separated from the ends of heat transfer elements (17, 18) by rubber sheets (1) which serve to provide heat insulation and sealing and are provided with holes (2, 3) for the circulation of a medium.