We present a spatial analysis of the soft X‐ray and Hα emissions from the outflow of the starburst galaxy M82. We find that the two emissions are tightly correlated on various scales. The O VII triplet of M82, as resolved by X‐ray grating observations of XMM‐Newton, is dominated by the forbidden line, inconsistent with the thermal prediction. The O VII triplet also shows some spatial variations. We discuss three possible explanations for the observed O VII triplet, including the charge exchange at interfaces between the hot outflow and neutral cool gas, a collisional non‐equilibrium‐ionization recombining plasma, and resonance scattering (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)