A new compact detector for measuring the velocity distribution of He atoms scattered from an oriented single‐crystal surface by the time‐of‐flight (TOF) method is described. In this system the scattered atoms are tagged by exciting them to the 23Smetastable state by cross bombardment with a pulsed electron beam. After traversal of a given flight path (80.9 mm), the metastables are detected by a multichannel‐plate electron multiplier, and their TOF distribution is recorded. The incident supersonic He beam is generated by a nozzle source, resulting in a very narrow energy distribution of the incident beam. The angular and energy resolutions of the detector are analyzed and its advantages and limitations are described. Finally, a demonstration of the performance of the instrument in inelastic scattering from a Cu(100) surface is presented.