An infrared (IR) spectrometer (20) for IR spectroscopic investigation of a test sample (1) in a first wavenumber range WB1, comprising a sample container (1a) for the test sample (1), wherein the sample container (1a) is transparent to IR radiation in the first wavenumber range WB1, and wherein the IR spectrometer (20) comprises a measuring device for determining the temperature of the test sample (1), is characterized in that the measuring device comprises an IR sensor (2) which measures, without contact, the intensity of the IR radiation emitted by the sample container (1a), and the sample container (1a) is opaque to IR radiation in the second wavenumber range WB2. A simple and reliable measurement of the temperature of a test sample in an IR spectrometer is thereby enabled.