r0005">We examine 1) photocurrent from Cs₃Sb photocathode as a function of anode voltage below 200 V, 2) relationship between quantum efficiency for photoemission and fabrication condition by “sandwich method”, 3) recovery of photoemission by an additional Cs deposition and 4) effect of surface protection of Cs₃Sb photocathode by WO₃ and Cr₂O₃ film in the passive state. It was ascertained that deposition of 1 to 3-atomic-layer W or Cr film elongated lifetime of the photoemission after they became WO₃ or Cr₂O₃ in passive state due to oxidation.