  We analyzed the ASCA X-ray data of 40 nearby clusters of galaxies, whose
intracluster-medium temperature distributes in the range of 0.9--10 keV. We
measured the Si and Fe abundances of the intracluster medium, spatially
averaging over each cluster, but excluding the central $\sim 0.15 h_{50}^{-1}$
Mpc region in order to avoid any possible abundance gradients and complex
temperature structures. The Fe abundances of these clusters are 0.2--0.3 solar,
with only weak dependence on the temperature of the intracluster medium, hence
on the cluster richness. In contrast, the Si abundance is observed to increase
from 0.3 to 0.6--0.7 solar from the poorer to richer clusters. These results
suggest that the supernovae of both type-Ia and type-II significantly
contribute to the metal enrichment of the intracluster medium, with the
relative contribution of type-II supernovae increasing towards richer clusters.
We suggest a possibility that a considerable fraction of type-II supernova
products escaped from poorer systems.
