A linear type pulsed-laser time of flight atom-probe field ion microscope has been developed which uses laser pulses of 300 ps from a nitrogen laser for field desorbing surface atoms. It is a time of flight mass spectrometer and an ion energy analyzer of single atom detecting sensitivity with good mass and energy resolution. The new system is used to study the energy distribution of field desorbed inert gas atoms such as Ne+ and Ar+, and field evaporated metal ions. The formation of metal helide ions such as RhHe++, PtHe++ and PtHe2++, and metal hydride ions such as AuH+, AuH2+, and AuH3+ has been studied by observing both the mass spectra and the energy distributions. The formation of H+, H2+, and H3+ from atomically well defined metal surfaces under the influence of an applied field is also studied.