A multilayer ceramic substrate includes an inner layer portion and surface portions that sandwich the inner layer portion in the stacking direction and have an increased transverse strength because of the surface layer portion having a thermal expansion coefficient less than that of the inner layer portion. At least one of the surface portions covers peripheries of main-surface conductive films arranged on a main surface of an inner portion so as to leave central portions of the main-surface conductive films exposed, so that the main-surface conductive films function as via conductors, thereby eliminating the need to provide a via conductor in the surface portions.