Abstract: A device for the pyrometric measurement of the temperature of a graphite tube furnace for flameless atom absorption spectroscopy is described. According to the invention, a pyroelectric detector is used as radiation receptor. The radiation flux at high temperatures is limited by a cut-off filter which starts at about .lambda..gtoreq.1 .mu.m and which, at the same time, can be constructed as radiation collector lens. It preferably consists of germanium. The detector signal is amplified in preferably three amplification stages which are connected under microprocessor control in dependence on the preselectable temperature ranges of the graphite tube furnace. A temperature measuring range from room temperature to 3,000.degree. C. is achieved.