One can see that the chemical potential thus obtained is shifted downward relative to the LHB with hole doping. One can also see that the valence-band maximum (VBM) of the LHB is shifted in k -space from ∼ ( π/ 2 , π/ 2) toward (0,0) with hole doping. Remarkably, the QP band stays almost at the same position in the E - k space in this plot and the E$_{F}$ crossing point, namely, k$_{F}$ in the nodal direction is shifted toward (0,0) following the downward chemical potential with hole doping. From Figs. 1-4 one can conclude that the lightly-doped Bi2212 shows a rigid-band-like shift of the LHB (except for the small shift toward k ∼ (0 , 0)) and the nodal QP just above the LHB, analogous to the case of Bi2201 and Na-CCOC. This behavior is different from LSCO, where the LHB stays almost at the same energy and the clear QP band is seen well ( ∼− 0 . 5 eV) above the LHB. In the antiferromagnetic (AF) insulating state of the undoped compound, the maximum of the LHB along the nodal direction should occur on the AF zone boundary, that is, exactly at ( π/ 2 , π/ 2) due to the folding of the BZ in the AF state. Without the long-range order, on the other hand, k$_{F}$ can in principle take any value. Therefore, it is interesting to see how the k$_{F}$ evolves as a function of p . In order to see this, we have plotted in Fig. 4(f) the doping dependence of the k$_{F}$ position determined from the MDC peak position at E$_{F}$ as a function of p . One can see from the figure that the LHB in lightly-doped Bi2212 indeed moves toward ( π/ 2 , π/ 2) with decreasing hole concentration. The results for Na- CCOC ( p =0, 0.05, 0.1, 0.12) also showed the same behavior $^{8}$. On the other hand, k$_{F}$ in LSCO extrapolates to ∼ (0 . 44 π, 0 . 44 π ) and not to ( π/ 2 , π/ 2) until p ≃ 0.03. (For undoped La$_{2}$CuO$_{4}$, a tiny amount of holes are doped due to excess oxygens and faint E$_{F}$ spectral weight appears at ( π/ 2 , π/ 2)). This can be understood as due to the separated features of the LHB and the QP band crossing E$_{F}$ in LSCO. This observation again points to the similarity between Bi2212, Bi2201 and Na-CCOC concerning the evolution of the electronic structure. From the present data, one can also obtain an important implication for the doping dependence of spectra across the insulator-superconductor transition (between p =0.06 and 0.075) in Bi2212. Nodal spectra in the superconducting phase ( p =0.075) have a sharp QP peak around E$_{F}$ without a gap, whereas nodal spectra in the insulating phase ( p =0.06) have finite shoulder-like spectral weight (weak and broad QP peak) around E$_{F}$ with a ∼ 9 meV leading-edge gap. It therefore appears that the system shows superconductivity when the nodal spectra show a sharp QP peak crossing E$_{F}$ . This behavior is consistent with the 5