A laminated and bonded structure includes plural plates. The plates include first and second plates. The plates are laminated and bonded to each other with an adhesive agent. The first and second plates have laminated surfaces bonded to each other. A first escape groove is defined in the laminated surface of at least one of the first and second plates. The first escape groove guides the adhesive agent along the laminated surface. The first escape groove includes an outlet portion in an outer peripheral side surface of the at least one of the first and second plates. The outer peripheral side surface intersects with the laminated surfaces. One of the first and second plates defines a recessed first reservoir portion being capable of accumulating the adhesive agent passing through the first escape groove. The first reservoir portion communicates with the first escape groove.