A specially designed time‐of‐flight spectrometer has been constructed for studying the ions emitted from an opaque surface in vacuum under bombardment by a Q switched laser beam. Since some of the ions to be studied are emitted with considerable kinetic energy, the spectrometer allows one to make independent measurements of them/eof the ions and of their initial kinetic energies. No other spectrometer design permits simultaneous measurements to be made of these two parameters during the interval of a single laser pulse. The design considerations involved in the construction of this spectrometer are described in some detail.