For the development of the ionizer with low discharge voltage and the photounit at ambient condition, a novel porous silicon(PS) fabricated by combining the electrochemical anodization in HF solution under light with hydrothermally iron-passivated is introduced. The characteristics of electron emission and photo-electricity response at ambient condition were studied. The results show that this PS can emit electrons steadily for 2[EQUATION]3 min, and there is positive output voltage ([EQUATION] 120 mV) in the dark and the negative output voltage ([EQUATION]30 mV) under illumination. This indicates that the novel PS holds a potential to be exploited as the ionizer with low discharge voltage and the special photounit at ambient condition.