  We have investigated both static and dynamic magnetic properties of
polycrystalline CaRu$_{1-x}$Sc$_{x}$O$_{3}$ system in order to clarify the role
of Sc ions as a disorder for magnetic ordering. We have observed typical
features of a ferromagnetic cluster glass state below around 40 K: (i) a broad,
frequency-dependent peak in the ac magnetic susceptibility, (ii) a slow
relaxation of the magnetization, and (iii) a continuous increase in the dc
magnetic susceptibility in field cooling process. The composition dependence of
characteristic parameters for the cluster glass state suggests that chemical
segregation can hardly explain the clustering mechanism. We propose a possible
picture that the ferromagnetic clusters are distributed uniformly and form the
glassy state embedded in the paramagnetic and metallic host of CaRuO$_{3}$.
