A sensitive x‐ray detection system has been used in the recording of soft x‐ray appearance potential spectra with an electron excitation current of a few microamperes covering a sample area of 1 cm2. The system included a 6&mgr; thick aluminum foil, a cesium iodide photocathode, a continuous‐channel electron multiplier, and conventional pulse‐counting electronics. The aluminum foil was placed over the entrance window of the detector in order to filter out the ultraviolet and extreme‐soft x‐ray emissions from the sample prior to detection of the soft x rays that passed through the foil. The transmitted soft x rays were incident on a cesium iodide photocathode and the resulting photoelectron events were individually detected with a high‐gain electron multiplier whose output pulses were processed with pulse‐counting electronics.