  We have performed an angle-resolved photoemission study of the two-leg ladder
system Sr$_{14-x}$Ca$_x$Cu$_{24}$O$_{41}$ with $x$= 0 and 11. "Underlying Fermi
surfaces" determined from low energy spectral weight mapping indicates the
quasi-one dimensional nature of the electronic structure. Energy gap caused by
the charge density wave has been observed for $x$=0 and the gap tends to close
with Ca substitution. The absence of a quasi-particle peak even in $x$=11 is in
contrast to the two-dimensional high-$T_c$ cuprates, implying strong carrier
localization related to the hole crystalization.
