  Using our deep ~120 ks Chandra observation, we report on the results from our
spatially-resolved X-ray spectral analysis of the "oxygen-rich" supernova
remnant (SNR) 0540-69.3 in the Large Magellanic Cloud. We conclusively
establish the nonthermal nature of the "arcs" in the east and west boundaries
of the SNR, which confirms the cosmic-ray electron acceleration in the
supernova shock (B ~ 20-140 microG). We report tentative evidence for Fe
overabundance in the southern region close to the outer boundary of the SNR.
While such a detection would be intriguing, the existence of Fe ejecta is not
conclusive with the current data because of poor photon statistics and limited
plasma models. If it is verified using deeper X-ray observations and improved
plasma models, the presence of Fe ejecta, which was produced in the core of the
supernova, near the SNR's outer boundary would provide an intriguing
opportunity to study the explosive nucleosynthesis and the ejecta mixing in
this young core-collapse SNR. There is no evidence of X-ray counterparts for
the optical O-rich ejecta in the central regions of the SNR.
