In the dilatonic domain wall model, we study the Schwarzschild black hole a
s a solution to the Kaluza-Klein zero mode effective action which is equiva
lent to the Brans-Dicke (BD) model with a potential. This can describe the
large Randall-Sundrum (RS) black hole whose horizon is to be the intersecti
on of the black cigar with the brane. The black cigar located far from the
five-dimensional anti-de Sitter (AdS(5)) horizon is known to be stable, but
any explicit calculation for stability of the RS black hole at z = 0 has n
ot yet been performed. Here its stability is investigated against the z-ind
ependent perturbations composed of odd-even parities of graviton (h(mu nu))
and BD scalar(h(44)=2 phi). It seems that the RS black hole is classically
unstable because it has a potential instability at a wavelength lambda >1/
(2k). However, this is not allowed inside an AdS(5) box of the size 1/(2k).
Thus the RS black hole becomes stable. The RS black hole can be considered
as a stable remnant at z=0 of the black cigar.