The electrical characteristics of porous silicon field emitter arrays (PSFEAs) was studied. The surface of silicon field emitters was modified by electrochemical etching with HF: ethanol solution. Porous silicon consists of a high density of submicroscopic fibrils which serve as increased emission sites per tip, hence significantly improving the emission characteristics. PSFEAs exhibited low turn-on voltage and high emission current with small current fluctuation and good reproducibility.