Results are given on the current of holes through an insulating double layer of SiO2and Si3N4on silicon. The holes originated from an avalanchingp‐njunction in the silicon and were injected into the SiO2. The results can be explained by assuming a space‐charge‐limited hole current in the SiO2in the presence of traps exponentially distributed in energy. A value of about 10−3cm2V−1sec−1was found for &mgr;, the hole mobility in the SiO2.