A cermet tool, comprising: not less than 75 volume% and not more than 95 volume% of a hard phase; and not less than 5 volume% and not more than 25 volume% of a binder phase, wherein the hard phase is composed of (a) a first hard phase with a core-rim structure composed of a core portion with a composite carbonitride phase of Ti, Nb, and Mo and a peripheral portion with a composite carbonitride phase of Ti, Nb, Mo, W, and Zr [hereinafter, referred to as (Ti, Nb, Mo, W, Zr) (C, N)] or a composite carbonitride phase of Ti, Nb, Mo, and W [hereinafter, referred to as (Ti, Nb, Mo, W) (C, N)], (b) a second hard phase with a core-rim structure composed of both a core portion and a peripheral portion with the (Ti, Nb, Mo, W, Zr) (C, N) phase or the (Ti, Nb, Mo, W) (C, N) phase, and (c) a third hard phase composed of a composite carbonitride phase of Ti, Nb, and Mo, the binder phase is composed of an element having at least one selected from the group consisting of Co, Ni, and Fe as a main component, when a maximum content of a concentration of the Nb element in a surface region that is within a range from a surface of the cermet tool to a depth of 300 μm is Nbs and an internal content of a concentration of the Nb element in an internal region that is deeper inside from the surface region is Nbi, Nbs/Nbi is not less than 0.8 and not more than 1.2, when a maximum content of a concentration of the W element in the surface region is Ws and an internal content of a concentration of the W element in the internal region is Wi, Ws/Wi is not less than 1.0 and not more than 1.5, and, in a cross section of the internal region of the cermet tool, when an area ratio of the first hard phase is A1, an area ratio of the second hard phase is A2, an area ratio of the third hard phase is A3, and an area of the entire hard phase is 100 area%, the A1 is not less than 75 area% and not more than 95 area%, the A2 is not less than 4 area% and not more than 24 area%, and the A3 is not less than 1 area% and not more than 24 area%, wherein Nbs, Nbi, Ws and Wi are obtained as follows: the cermet tool is polished by tilting at 10 degrees relative to the surface of the cermet tool and a cross-section of the polished surface is observed with an SEM, and a concentration of respective elements is obtained by using an EDS attached to the SEM; the concentrations of Nb and W in 10 spots with intervals of 10 μm in a vertical direction from the surface of the cermet tool are measured and the maximum contents among them are defined as Nbs and Ws, and the concentrations of Nb and W in arbitrary 10 spots in positions of 500 μm from the surface are measured and the average values are defined as Nbi and Wi, and A1, A2 and A3 are obtained from an SEM image of the cross-section of the polished surface of the cermet tool, obtained by tilting at 10 degrees relative to the surface of the cermet tool, the polished surface being enlarged at a magnification from 2000 to 10000 by a method using commercially available image analysis software or a method using Fullman's expression: dm = (4π). (NL/NS) wherein dm denotes an average particle size, π denotes the circular constant, NL denotes the number of hard phases per unit length hit by an arbitrary straight line on the cross-section, and NS denotes the number of hard phases contained in an arbitrary unit area. (a) a first hard phase with a core-rim structure composed of a core portion with a composite carbonitride phase of Ti, Nb, and Mo and a peripheral portion with a composite carbonitride phase of Ti, Nb, Mo, W, and Zr [hereinafter, referred to as (Ti, Nb, Mo, W, Zr) (C, N)] or a composite carbonitride phase of Ti, Nb, Mo, and W [hereinafter, referred to as (Ti, Nb, Mo, W) (C, N)], (b) a second hard phase with a core-rim structure composed of both a core portion and a peripheral portion with the (Ti, Nb, Mo, W, Zr) (C, N) phase or the (Ti, Nb, Mo, W) (C, N) phase, and (c) a third hard phase composed of a composite carbonitride phase of Ti, Nb, and Mo, the cermet tool is polished by tilting at 10 degrees relative to the surface of the cermet tool and a cross-section of the polished surface is observed with an SEM, and a concentration of respective elements is obtained by using an EDS attached to the SEM; the concentrations of Nb and W in 10 spots with intervals of 10 μm in a vertical direction from the surface of the cermet tool are measured and the maximum contents among them are defined as Nbs and Ws, and the concentrations of Nb and W in arbitrary 10 spots in positions of 500 μm from the surface are measured and the average values are defined as Nbi and Wi, and A1, A2 and A3 are obtained from an SEM image of the cross-section of the polished surface of the cermet tool, obtained by tilting at 10 degrees relative to the surface of the cermet tool, the polished surface being enlarged at a magnification from 2000 to 10000 by a method using commercially available image analysis software or a method using Fullman's expression: dm = (4π). (NL/NS) wherein dm denotes an average particle size, π denotes the circular constant, NL denotes the number of hard phases per unit length hit by an arbitrary straight line on the cross-section, and NS denotes the number of hard phases contained in an arbitrary unit area. dm = (4π). (NL/NS) wherein dm denotes an average particle size, π denotes the circular constant, NL denotes the number of hard phases per unit length hit by an arbitrary straight line on the cross-section, and NS denotes the number of hard phases contained in an arbitrary unit area.