Tip shapes of Si field emitter arrays, fabricated by a conventional dry etching process, have been modified by focused ion-beam (FIB) irradiation to obtain a sharp cone shape. Flat-topped Si tips could be sharpened by localized sputtering using FIBs for a short time. Tip shape inspections and repairs were also performed using a FIB system combined with an electron-beam column to remove metal residues and melted emitters.