The design procedure and the experimental details are given for the construction of a magnetic deflection system which has been used in an electron beam spectrometer to measure the angular distribution of the energy loss spectra of thin solid films. A collimated electron beam is deflected in such a way that it is incident on the specimen at the angle of scatter at which measurements are required. Electrons which emerge normally from the far side of the specimen are then momentum analyzed. The deflection was found to be proportional to current up to an angle of at least 0.04 rad.