  We observed the southwestern region of the Cygnus Loop in two pointings with
\textit{XMM-Newton}. The region observed is called the "blow-out" region that
is extended further in the south. The origin of the "blow-out" is not well
understood while it is suggested that there is another supernova remnant here
in radio observation. To investigate the detail structure of this region in
X-ray, we divided our fields of view into 33 box regions. The spectra are well
fitted by a two-component nonequilibrium ionization model. The emission measure
distributions of heavy elements decrease from the inner region to the outer
region of the Loop. Then, we also divided our fields of view into 26 annular
sectors to examine the radial plasma structure. Judging from metal abundances
obtained, it is consistent with that the X-ray emission is the Cygnus Loop
origin and we concluded that high-$kT_{e}$ component ($\sim$0.4 keV) originates
from the ejecta while low-$kT_{e}$ component ($\sim$0.2 keV) is derived from
the swept-up interstellar medium. The flux of low-$kT_{e}$ component is much
less than that of high-$kT_{e}$ component, suggesting the ISM component is very
thin. Also, the relative abundances in the ejecta component shows similar
values to those obtained from previous observations of the Cygnus Loop. We find
no evidence in X-ray that the nature of the "blow-out" region originated from
the extra supernova remnant. From the ejecta component, we calculated the
masses for various metals and estimated the origin of the Cygnus Loop as the
core-collapse explosion rather than the Type Ia supernova.
