The 0 1s x-ray photoemission spectra of (Bi,Pb)2Sr2CaCu20 and Bi2Sr2CaCu20"single crystals are presented. The same spectra are also measured in the case of ceramics. Two features are clearly identified. It is found that the shoulder possessing the smallest binding energy is more pronounced for the single crystal with Pb than that of the pure compound of the same 2:2:1:2phase. This suggests that the main contribution to the 0 1s x-ray photoemission spectroscopy spectrum of a lead-free Bi2Sr2CaCu20"compound is due to oxygens in the Bi-0 plane of a cleaved surface.