To prevent the generation of a crack on a ceramic circuit board having a protruded portion, to increase bending strength, and to prevent a short circuit and the like.

A wax material layer is formed on at least one surface of the ceramic substrate along a plurality of circuit patters with the wax material layer comprising an Ag-Cu-In-Ti-based wax material. A metal plate is bonded via the wax material, and undesired portions of the metal plate are etched. In this manner, the ceramic circuit substrate is provided that is formed with a circuit pattern comprising the metal plate and formed with the protruded portion composed of the wax material layer protruding from the outer edge of the metal plate, wherein the protruding portion has a maximum surface roughness Rmax of 5 to 50 m, and bond strength (peel strength) between the ceramic material and the metal plate is 20 kN/m or larger.