  We report on the detection of the Sunyaev -- Zel'dovich (SZ) signals toward
the most luminous X-ray cluster RXJ1347-1145 at Nobeyama Radio Observatory (21
and 43 GHz) and at James Clerk Maxwell Telescope (350 GHz). In particular the
latter is the first successful detection of the SZ temperature increment in the
submillimeter band which resolved the profile of a cluster of galaxies. Both
the observed spectral dependence and the radial profile of the SZ signals are
fully consistent with those expected from the X-ray observation of the cluster.
The combined analysis of 21GHz and 350GHz data reproduces the temperature and
core-radius of the cluster determined with the ROSAT and ASCA satellites when
we adopt the slope of the density profile from the X-ray observations.
Therefore our present data provide the strongest and most convincing case for
the detection of the submillimeter SZ signal from the cluster, as well as in
the Rayleigh -- Jeans regime. We also discuss briefly the cosmological
implications of the present results.
