  We discuss the anomalous magnetic moment of fermion in a realistic SU(3)
model of gauge-Higgs unification compactified on an orbifold S^1/Z_2 including
Z_2-odd bulk mass for fermions. An operator analysis implies that the anomalous
magnetic moment should be finite and predictable, even though higher
dimensional gauge theories are non-renormalizable. Our main purpose is to
clarify the cancellation mechanism of the UV divergences appearing in various
types of Feynman diagrams. The cancellation of divergence turns out to take
place between the contributions of the "partners" in the Higgs-like mechanism
present in the non-zero Kaluza-Klein modes to form massive gauge bosons. It is
also argued that the cancellation may be attributed to the quantum mechanical
SUSY hidden in the scenario of gauge-Higgs unification.
