In a temperature measuring device (1) an IR-radiation detector (2) and a reference element (3) are provided, connected to a surface (6) of an object (7) in a heat-conducting fashion, with a first area (4) with high emissivity and a second area (5) with high reflectivity formed at the reference element (3), and the IR-radiation detector (2) is equipped for a separate detection of IR-radiation (9, 10, 11) from the first and second areas (4, 5) and a surface area (12) of the object (7). A computer (13) in the IR-radiation detector (2) is equipped to deduct a temperature measurement for the object (7), corrected for emissions and reflections from the detected IR-radiations (9, 10, 11).