In a multilayer ceramic substrate manufactured by a non-shrinking process, a bonding strength of an external conductive film formed on a primary surface of the multilayer ceramic substrate is increased. After a laminate of a multilayer ceramic substrate is formed from first ceramic layers and second shrinkage suppressing ceramic layers, and an underlayer is formed along one primary surface of the multilayer ceramic substrate, an external conductive film is formed on the underlayer. A non-sintering ceramic material powder in a non-sintered state is included in both the external conductive film and the underlayer, and this non-sintering ceramic material powder is fixed due to diffusion of a glass component from the first ceramic layers.