We propose to observe an isolated elliptical galaxy NGC720 with Suzaku. Isolated elliptical galaxies are important to probe the ISM metal abundance, since their hot gas is not affected by the amibient bright intracluster medium which often exists around X-ray bright elliptical galaxies. Suzaku is expected to measure the Oxygen abundance in the ISM bettern than XMM-Newton and constrain the origin of metals in the ISM and also ICM. Dark matter content around elliptical galaxies can also be constrained better than XMM-Newton. Such a measurement is difficult for X-ray bright galaxies due to the superposition of the cluster potential.