A possibility to detect X-rays from star-formation burst activities in
proto-elliptical galaxies is considered. The X-ray flux of an emission due to
inverse Compton scattering of the cosmic microwave background (CMB) by high
energy electrons accelerated in SNRs is shown to increase as z increases far
beyond unity, since the local CMB flux largely increases in association with a
z-increase. The flux is estimated for the case of a very high rate of type II
supernovae at an initial star formation burst of a proto-elliptical galaxy and
is found to be detectable with a future large X-ray telescope such as intended
in the XEUS mission.Comment: 4 pages, 1 figure, will appear in PAS