Abstract: A pyrometric measurement method and a multi-channel pyrometer for determining the temperature T.sub.o of surfaces with different emissivities by measuring the spectral signal voltages U.sub.j at j=1 to n effective wavelengths. The invention obtains, by infrared measurements at at least two effective wavelengths, information concerning the object temperature and the emissivity relationships actually existing for selected surface materials, such as those which are typical for a user. The spectral signal voltages U.sub.ij are ascertained as a function of the difference U.sub.oj -U.sub.uj for a discrete number i=1 to n of surface materials differing in emissivity and the hypothetically possible spectral voltages U.sub.oij and, from these, the probable object temperature T.sub.o and the probable applicable surface material are determined from the measured spectral signal voltages U.sub.j, using the functional relationship that has been established for each emissivity .epsilon..sub.ij.