$<$1.60 & 1.13$\pm$0.41 & 0.87$\pm$0.31 & 0.63$\pm$0.17\
region & & &\
0–2’ & & &\
0–2’ & & &\
2–4’ & & &\
4–6’ & & &\
6–8’ & & &\
8–10’ & & &\
10–12’ & & &\
12–28’ & & &\
\
\
\
\
\

Table 3 shows the best-fit results for each region. The fit is acceptable for all the regions. The O abundance is measured up to 10–12’ and Mg, Si and Fe to 12–28’ for the first time. However, the Ne abundance is not reliable because Ne line measurements are influenced by nearby Fe-L lines, which cannot be resolved with the resolution of the XIS. It can be seen from Figure 3 that the Galactic emission is well reproduced and significantly contributes to the spectra in the outer region, and thus it must be accurately estimated to derive the O abundance of NGC 4636. As a result, even for O, the abundances in the outer regions are determined up to 10’ with $\sim$30% accuracy. Even if we allow the temperature of the BREMSS (7keV) component to vary, the metal abundances only change within errors so we believe that they are reliable. The luminosity of 