  We present ISOPHOT spectrophotometric observations of SS433 at four different
orbital phases in 1996 and 1997. The HeI+HeII lines in both spectra of SS433
and the Wolf-Rayet star WR147, a WN8+BO5 binary system, closely match. The
2.5-12 micron continuum radiation is due to an expanding wind free-free
emission in an intermediate case between optically thick and optically thin
regime. A rough mass loss rate evaluation gives about 1.4 10^{-4} M_sun/yr.
Results are consistent with a Wolf-Rayet-like companion to the compact object
in SS433.

Astrophysics