A semiconductor electron telescope for measuring the electron energy distribution in the radiation-belt is described. It has three energy ranges: E
e1≥ 0.25 MeV, B
e2≥0.5 MeV and E
e3≥0.8MeV. The telescope consists of three Si(Au) surface barrier detectors. Details of the design and performance are reported. This telescope has been used in some space detections. The results show that its quality is satisfactory.