  We report on an {\it XMM-Newton} observation of the supernova remnant (SNR)
\object{DEM L241} in the Large Magellanic Cloud. In the soft band image, the
emission shows an elongated structure, like a killifish, with a central compact
source. The compact source is point-like, and named as XMMU J053559.3$-$673509.
The source spectrum is well reproduced with a power-law model with a photon
index of $\Gamma = 1.57$ (1.51--1.62) and the intrinsic luminosity is
$2.2\times 10^{35} \mathrm{ergs s^{-1}}$ in the 0.5--10.0 keV band, with the
assumed distance of 50 kpc. The source has neither significant coherent
pulsations in $2.0\times 10^{-3}$ Hz--8.0 Hz, nor time variabilities. Its
luminosity and spectrum suggest that the source might be a pulsar wind nebula
(PWN) in DEM L241. The spectral feature classifies this source into rather
bright and hard PWN, which is similar to those in Kes 75 and B0540$-$693. The
elongated diffuse structure can be divided into a ``Head'' and ``Tail'', and
both have soft and line-rich spectra. Their spectra are well reproduced by a
plane-parallel shock plasma ({\it vpshock}) model with a temperature of
0.3--0.4 keV and over-abundance in O and Ne and a relative under-abundance in
Fe. Such an abundance pattern and the morphology imply that the emission is
from the ejecta of the SNR, and that the progenitor of DEM L241 is a very
massive star, more than 20 M\sun. This result is also supported by the
existence of the central point source and an OB star association, LH 88. The
total thermal energy and plasma mass are $\sim 4\times 10^{50}$ ergs and $\sim
200$ M\sun, respectively.
