  It is shown that the superradiance modes always exist in the radiation by the
$(4+n)$-dimensional rotating black holes. Using a Bekenstein argument the
condition for the superradiance modes is shown to be $0 < \omega < m \Omega$
for the scalar, electromagnetic and gravitational waves when the spacetime
background has a single angular momentum parameter about an axis on the brane,
where $\Omega$ is a rotational frequency of the black hole and $m$ is an
azimuthal quantum number of the radiated wave.
