We have studied the annealing behavior of anodically etched porous Zn (p-Zn) as a function of annealing time. It is found that 10 min ambient air annealing of Zn yields efficient UV luminescence with a very weak deep-level defect-related luminescence. The emergence of the green luminescence band is observed with an increase of annealing time. Scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) have been performed on annealed p-Zn. STM studies reveal a more smooth surface for p-Zn annealed for a short period. STS analysis shows a good agreement with observed PL spectra, especially concerning the existence or absence of defect-related luminescence. (C) 2003 Elsevier Science B.V. All rights reserved.