A thermomagnetic generator which converts thermal energy to electrical energy without intermediate conversion to mechanical work and which works at temperatures in the range from −20° C. to 200° C. comprises a thermomagnetic material selected from, for example, (1) compounds of the general formula (I) (AyBy−1)2+δCwDxEz  (I) where A is Mn or Co, B is Fe, Cr or Ni, C, D and E at least two of C, D and E are different, have a non-vanishing concentration and are selected from P, B, Se, Ge, Ga, Si, Sn, N, As and Sb, where at least one of C, D and E is Ge or Si, δ is a number in the range from −0.1 to 0.1, w, x, y, z are numbers in the range from 0 to 1, where w+x+z=1.