  In order to clarify magnetic properties of filled skutterudites, we analyze
the Anderson model including seven $f$ orbitals hybridized with an $a_{\rm u}$
conduction band using a numerical technique. For $n$=2 corresponding to
Pr-based filled skutterudites, where $n$ is the local $f$-electron number, even
if the ground state is a singlet, there remain significant magnetic
fluctuations from a triplet state with a small excitation energy. This result
can be understood by the fact that $f$-electron states are clearly
distinguished as itinerant and localized ones in the filled skutterudite
structure. This picture also explains the complex results for $f$-electron
magnetic susceptibility and entropy for $n$=1$\sim$13.
