  We studied magnetic-field induced microwave absorption in 100-200 nm thick
La$_{0.7}$Sr$_{0.3}$MnO$_{3}$ films on SrTiO$_{3}$ substrate and found a
low-field absorption with a very peculiar angular dependence: it appears only
in the oblique field and is absent both in the parallel and in the
perpendicular orientations. We demonstrate that this low-field absorption
results from the ferromagnetic resonance in the multidomain state (domain-mode
resonance). Its unusual angular dependence arises from the interplay between
the parallel component of the magnetic field that drives the film into
multidomain state and the perpendicular field component that controls the
domain width through its effect on domain wall energy. The low-field microwave
absorption in the multidomain state can be a tool to probe domain structure in
magnetic films with in-plane magnetization.
