To study the two-dimensional Fermi energy band dispersion of Bi2Sr2CaCU2Oy in the vicinity of the Fermi level, photoelectron intensity angular distributions (PIADs) was measured at room temperature using non-polarized He I excitation light (21.2 eV) in normal incidence geometry. Strong photoelectron peaks appeared at the (M) over bar points in the PIAD at the Fermi level. They are attributed to the Fermi energy band which disperses toward both the F and Z points at higher binding energies, however, only the dispersion from the (M) over bar toward the Z points with increasing binding energy was observed. The disappearance of photoelectron peaks of Fermi energy band in the first Brillouin zone was explained by the transition matrix element from d(x)(-y)(2)(2) atomic orbital to p and f final states for the case of non-polarized light at normal incidence. (c) 2007 Elsevier B.V. All rights reserved.