  We present the first results of an XMM-Newton observation of the central
X-ray source in the Cas A supernova remnant. The spectrum can be fit equally
well with an absorbed steep power law (alpha~3, N_H~1.5x10^22 cm^-2) or with a
bremsstrahlung with temperature kT~2.4 keV and N_H~10^22 cm^-2. A blackbody
model (kT~0.7 keV) gives a slightly worse fit and requires a column density
N_H~5x10^21 cm^-2 and an emitting area with radius ~0.3 km (for d=3.4 kpc). A
search for pulsations for periods longer than 150 ms gave negative results. The
3 sigma upper limits on the pulsed fraction are ~13% for P>0.3 s and ~7% for
P>3 s. The overall properties of the central X-ray source in Cas A are
difficult to explain in terms of a rapidly spinning neutron star with a
canonical magnetic field of ~10^12 G, and are more similar to those of slowly
rotating neutron stars such as the Anomalous X-ray Pulsars.
