Abstract: A diamond-clad machining tool is prepared by the steps of (a) forming a film of diamond of 10 to 1000 .mu.m thickness by the method of vapor-phase deposition on the surface of a temporary substrate of, e.g., silicon, (b) bonding the diamond film as borne by the temporary substrate to the surface of a base body of the tool by brazing and (c) removing the temporary substrate, e.g., by grinding to leave the diamond film bonded to the base body of the tool by brazing. The method is advantageous in the versatility in respect of the material of substrate on which a diamond film is deposited from the vapor phase as well as in the firmness of bonding between the cladding layer and the base body of the tool in comparison with the conventional vapor-phase deposition method of diamond directly to the surface of the base body of a tool.