After a wet blasting treatment for jetting a slurry, which contains spherical alumina as abrasive grains in a liquid, to the surface of a ceramic substrate 10 of aluminum nitride sintered body so that the ceramic substrate 10 has a residual stress of not higher than −50 MPa and so that the surface of the ceramic substrate 10 to be bonded to the metal plate 14 has an arithmetic average roughness Ra of 0.15 to 0.30 μm, a ten-point average roughness Rz of 0.7 to 1.1 μm and a maximum height Ry of 0.9 to 1.7 μm while causing the ceramic substrate to have a flexural strength of not higher than 500 MPa and causing the thickness of a residual stress layer 10a formed along the surface of the ceramic substrate 10 to be 25 μm or less, the metal plate 14 of copper or a copper alloy is bonded to the ceramic substrate 10, which is obtained by the wet blasting treatment, via a brazing filler metal 12 to produce a metal/ceramic bonding substrate which has an excellent bonding strength of the ceramic substrate 10 to the metal plate 14 and which has an excellent heat cycle resistance.