Method for manufacturing ceramic substrate and ceramic substrate

A ceramic substrate produced by a method for manufacturing a ceramic substrate comprising:

• a first step of forming a green stacked body including:
• a base layer defining a ceramic substrate after firing, the base layer including ceramic powder and glass material;
• an electrode disposed on at least one principal surface of the base layer;
• and
• a constraining layer disposed so as to be in contact with the at least one principal surface of the base layer and the electrode disposed thereon, the constraining layer being primarily composed of ceramic powder that is not substantially sintered at a sintering temperature of the base layer;
• a second step of firing the green stacked body to obtain a fired stacked body having a sintered base layer, the constraining layer, and a reaction layer formed by a reaction between the base layer and the constraining layer during firing;
• and
• a third step of removing the constraining layer from the sintered base layer by vibrating media that are disposed so as to be in contact with the constraining layer;
• wherein
• at least a portion of the reaction layer remains after the third step of removing the constraining layer.