In this study, diffusion of single adatoms and mono-vacancies on Au(100), Ag(110) and W(100) was investigated. The measurements on Au(100) and Ag(110) were conducted with using Scanning Tunneling Microscope (STM), whereas measurements on W(100) were conducted with using Field Ion Microscope (FIM). The activation energy for Au adatom diffusion on Au(100) surface was found to be 0.32+ or - 0.02eV and diffusion of mono-vacancies has been observed. The vacancies were created via Ne+ ion sputtering. Preliminary values of jump rates mono-vacancy diffusion has been determined. For measurements on Ag(110) conditions of creation mono-vacancies via Ne+ ion sputtering has been determined. For measurements on W(100), the activation energy for self-diffusion of adatom was found to be 1.58 + or - 0.19 eV. The morphology of W(100) surface and the diffusion mechanisms for diffusing W adatom on W(100) has been determined. Mono-vacancies resolved in FIM were previously created by using two alternative methods: via electric field evaporation of the surface and via Ne+ ion sputtering.