A cutting tool (1, 21, 31, 41) comprising a base material and a coating (15, 25, 35, 45) arranged on the base material; wherein: the coating (15, 25, 35, 45) comprises an α-Al 2 O 3 layer; the α-Al 2 O 3 layer is composed of a plurality of α-Al 2 O 3 particles; the α-Al 2 O 3 layer comprises a first region, a second region and a third region; the first region is a region sandwiched between an interface P1 on the base material side of the α-Al 2 O 3 layer and a virtual surface S1 that is located at a distance of 0.5 μm from interface P1 toward the surface side of the coating (15, 25, 35, 45); the second region is a region sandwiched between virtual surface S1 and a virtual surface S2 that is located at a distance of 1.0 μm from virtual surface S1 toward the surface side of the coating (15, 25, 35, 45); the third region is a region sandwiched between a surface P2 of the α-Al 2 O 3 layer or an interface P3 on the surface side of the coating (15, 25, 35, 45) of the α-Al 2 O 3 layer and a virtual surface S3 that is located at a distance of 1.0 μm from surface P2 or from interface P3 toward the base material side; the average particle diameter a of the α-Al 2 O 3 particles in the first region is 0.10 μm or more and 0.30 μm or less, the average particle diameter a measured using the method described in the description; the average particle diameter b of the α-Al 2 O 3 particles in the second region is 0.32 μm or more and 0.48 μm or less, the average particle diameter b measured using the method described in the description; the average particle diameter c of the α-Al 2 O 3 particles in the third region is 0.12 μm or more and 0.28 μm or less, the average particle diameter c measured using the method described in the description; and the ratio b/a between the average particle diameter b and the average particle diameter a is 1.5 or more and 5.0 or less. the coating (15, 25, 35, 45) comprises an α-Al 2 O 3 layer; the α-Al 2 O 3 layer is composed of a plurality of α-Al 2 O 3 particles; the α-Al 2 O 3 layer comprises a first region, a second region and a third region; the first region is a region sandwiched between an interface P1 on the base material side of the α-Al 2 O 3 layer and a virtual surface S1 that is located at a distance of 0.5 μm from interface P1 toward the surface side of the coating (15, 25, 35, 45); the second region is a region sandwiched between virtual surface S1 and a virtual surface S2 that is located at a distance of 1.0 μm from virtual surface S1 toward the surface side of the coating (15, 25, 35, 45); the third region is a region sandwiched between a surface P2 of the α-Al 2 O 3 layer or an interface P3 on the surface side of the coating (15, 25, 35, 45) of the α-Al 2 O 3 layer and a virtual surface S3 that is located at a distance of 1.0 μm from surface P2 or from interface P3 toward the base material side; the average particle diameter a of the α-Al 2 O 3 particles in the first region is 0.10 μm or more and 0.30 μm or less, the average particle diameter a measured using the method described in the description; the average particle diameter b of the α-Al 2 O 3 particles in the second region is 0.32 μm or more and 0.48 μm or less, the average particle diameter b measured using the method described in the description; the average particle diameter c of the α-Al 2 O 3 particles in the third region is 0.12 μm or more and 0.28 μm or less, the average particle diameter c measured using the method described in the description; and the ratio b/a between the average particle diameter b and the average particle diameter a is 1.5 or more and 5.0 or less.