A medical suture needle having a triangular cross section comprising: two first slanted and ground surfaces sandwiching a ridge, and a first bottom surface sandwiched between the two first slanted and ground surfaces, and two second slanted and ground surfaces sandwiching the ridge on a front end side of the first slanted and ground surfaces, and a second bottom surface sandwiched between the two second slanted and ground surfaces; wherein grind marks of the first slanted and ground surfaces are formed along the length of the medical suture needle, and grind marks of the second slanted and ground surfaces and the first and second bottom surfaces (13, 14) are formed crossing the length of the medical suture needle; and the ridge comprises a first cutting blade that is formed by an intersection of the two first slanted and ground surfaces, a ridge part that is formed on a body part side of the ridge where the two first slanted and ground surfaces do not intersect, and a second cutting blade that is formed by the intersection of the two second slanted and ground surfaces on a front end side of the ridge; the first bottom surface and the second bottom surface are formed as continuous curved surfaces and are formed slanted so that they approach the first cutting blade and the second cutting blade; wherein the length of the first cutting blade is within a range of 3 to 20 times the length of the second cutting blade, and wherein the second cutting blade is not aligned with the first cutting blade; characterised in that the medical suture needle is made of austenitic stainless steel having a fibrously extending structure and in that the second bottom surface is curved until a point that is formed by convergence of the second cutting blade, the two second slanted and ground surfaces and the second bottom surface, is positioned on the center side from the circumference surface of the material. two first slanted and ground surfaces sandwiching a ridge, and a first bottom surface sandwiched between the two first slanted and ground surfaces, and two second slanted and ground surfaces sandwiching the ridge on a front end side of the first slanted and ground surfaces, and a second bottom surface sandwiched between the two second slanted and ground surfaces; wherein grind marks of the first slanted and ground surfaces are formed along the length of the medical suture needle, and grind marks of the second slanted and ground surfaces and the first and second bottom surfaces (13, 14) are formed crossing the length of the medical suture needle; and the ridge comprises a first cutting blade that is formed by an intersection of the two first slanted and ground surfaces, a ridge part that is formed on a body part side of the ridge where the two first slanted and ground surfaces do not intersect, and a second cutting blade that is formed by the intersection of the two second slanted and ground surfaces on a front end side of the ridge; the first bottom surface and the second bottom surface are formed as continuous curved surfaces and are formed slanted so that they approach the first cutting blade and the second cutting blade; wherein the length of the first cutting blade is within a range of 3 to 20 times the length of the second cutting blade, and