Dissociative excitation of even quartet and sextet levels of the manganese atom by electron collisions with manganese diiodide molecules was studied experimentally. Twelve excitation cross-sections for transitions from quartet levels and 23 cross-sections for transitions from sextet levels were measured at an incident electron energy of 100 eV. The optical excitation function (OEF) was recorded in the range of electron energies 0‒100 eV for transitions originating at the 3d54s4de6DJ levels. The potential channels of dissociative excitation in the range of low electron energies (E < 22 eV) were discussed.