  The ferromagnetic resonance spectrum of a normally magnetized YIG disk, with
thickness of 4.75$\mu$m and radius of 80$\mu$m, is measured at room temperature
both by magnetic resonance force microscopy and by standard detection of the
microwave susceptibility. The comparison indicates that MRFM represents one of
the most potent means of obtaining the \emph{complete} FMR spectra of
micron-size samples. In the weak coupling regime, the measured data can be
quantitatively understood within the framework of the Damon and Eshbach model.
