Résumé dans la langue de publication A diamond sintered body tool having superior adhesion resistance and chipping resistance and high strength is provided. A diamond sintered body tool 20 includes a tool base material 22 including a diamond sintered body, and a surface layer 21 formed on a surface of the tool base material 22. The surface layer 21 includes at least one selected from the group of silicon, a silicon oxide, a silicon carbide, a silicon nitride and a solid solution thereof. The tool base material 22 has an inner portion 22b including a first content of an iron group metal, and a surface portion 22a surrounding the inner portion 22b and including a second content of the iron group metal, the second content being lower than the first content.