Spectra of the diffuse emission in the field of view of PSR B 0540−69 extracted from the XMM-Newton EPIC MOS1 data of the Obs. ID 01251201. The left panels show the spectra of region 1 located east of the PSR, the right panels show the spectra of the superbubble in the H ii region N 158. The upper diagrams show the fit with the NEI model, the lower diagrams with the NPSHOCK model.