A cutting tip for a drilling tool includes a cemented carbide cutting base 11, a diamond element 12 supported by the cutting base 11, and a bonding layer formed between the cutting base 11 and the diamond element 12 in order to bond them. The bonding layer 13 includes diffusion layers S1 and S2 in which one or two or more metals selected from a group consisting of Fe, Ni, Co, Ti, Zr, W, V, Nb, Ta, Cr, Mo, and Hf diffuses into at least one of the cemented carbide or the diamond.