Angle-resolved photoemission spectroscopy has been performed on Sr14-xCaxCu24O41 (x = 0-11.5) which consists of two-leg Cu2O3 ladders and edge-sharing CuO2 chains. A dispersive band with the periodicity of ladder sublattice is observed near the Fermi level (EF) for x=0. The band shows a minimum binding energy at ka= (2n + 1)π/2, suggesting that a Mott-Hubbard gap opens on the ladder. This indicates that copper atoms on the ladder take essentially the divalent state (Cu2+) and a majority of self-doped holes reside on the chain. We found that the Ca substitution causes a transfer of holes from the chain to the ladder. © 1998 Elsevier Science Ltd. All rights reserved.