A new capacitance method is described for the measurement of local, time‐varying or steady‐state film thickness in two‐phase flow studies. The method is suitable for use in simple and complex geometries, and works for either electrically nonconducting or slightly conducting fluids. Test data were obtained on bubbles of different lengths rising in a circular tube filled with water. Results for film thicknesses and bubble residence times showed good self‐consistency and agreement with other available data.