The authors investigated the property of cathodluminescence-like (CL-like) emission in the device of MEH-PPV sandwiched between two SiO2 layers. The authors observed in addition to the inherent electroluminescence of MEH-PPV, a shorter emission peak which is considered to be corresponding to HOMO-LUMO transition. From the relative change of these two peaks with the variation of the thickness of SiO2, The authors studied the electron acceleration ability of SiO2.