The paper describes the construction of a set-up for energy-dispersive x-ray diffraction measurements on weakly scattering (amorphous) samples. To minimise the effects of air scattering, the diffraction chamber can be evacuated to pressures below 10 Pa. The set-up is fully radiation safe. The x-ray optics can be aligned by means of small, DC-driven motors, while the x-ray beam is switched on. Some results of a thin (3mum) sputtered amorphous Fe₅₀B₅₀ film are shown to illustrate the performance of the set-up.