  We present results from spectral analysis of ASCA data on the NLS1 Mrk 507.
This galaxy was found to have an exceptionally flat ROSAT spectrum among the
NLS1s. The ASCA spectrum however shows a clear absorption feature in the energy
band below 2 keV, which partly accounts for the flat spectrum observed with the
ROSAT PSPC. The absorption is mainly due to cold gas with a column density of
(2-3)E21 cm-2. A reanalysis of the PSPC data indicates that the absorber is
slightly ionized, covers only part of the central source, or there is extra
soft thermal emission from an extended region. There is also evidence that the
X-ray absorption is complex; an edge feature marginally detected at 0.84 keV
suggests the presence of an additional high ionization absorber which imposes a
strong OVIII edge on the spectrum. After correction for the absorption, the
photon index of the intrinsic continuum, 1.8, obtained from the ASCA data is
quite similar to that of ordinary Seyfert 1 galaxies. Mrk 507 still has one of
the flattest continuum slopes among NLS1, but is no longer exceptional. The
strong optical FeII emission remains unusual in the light of the correlation
between FeII strengths and steepness of soft X-ray slope.
