Cemented carbide consisting of: first hard-phase particles (a) containing WC; second hard-phase particles (b) which contain carbonitride containing at least Ti and Nb; and a metallic binder phase (c) containing an iron-group element, the second hard-phase particle (b) including a granular core portion (ba) and a peripheral portion (bb) which covers at least a part of the core portion (ba), the core portion (ba) containing composite carbonitride expressed as Ti 1-X-Y Nb X W Y C 1-Z N Z, where X is 0.1 or more and 0.2 or less, Y is 0 or more and 0.05 or less, and Z is 0.3 or more and 0.6 or less, the peripheral portion (bb) being different in composition from the core portion (ba), wherein the content of WC in the first hard-phase particles is 99% by mass or more, the metallic binder phase is composed of not less than 90 atomic % Co, wherein in the core portion, optionally a total amount of V, Cr, and Mo occupied in a total amount of Ti, Nb, W, V, Cr, and Mo is smaller than 2 atomic %, characterised in that, the cemented carbide having an absolute value of a difference not greater than 10, between a ratio ( %) of an area occupied by the second hard-phase particles at a surface of the cemented carbide and a ratio ( %) of an area occupied by the second hard-phase particles in a region extending from the surface by 0.5 mm in a direction of depth, wherein the ratio ( %) of the area occupied by second hard-phase particles at the surface of the cemented carbide and the ratio ( %) of the area occupied by the second hard-phase particles in the region extending from the surface by 0.5 mm in the direction of depth are determined by the method described in the description, a volume ratio of the core portion (ba) in the cemented carbide is not lower than 2 volume % and not higher than 20 volume %, the volume ratio of the core portion (ba) occupied in cemented carbide is found by a method in which an area ratio of the core portion (ba) in an observation field of view is found by preparing and observing the cut plane with a SEM at a magnification of from 3000 to 5000x, and analyzing an image with image analysis software, then the area ratio is regarded as a volume ratio of the core portion (ba) occupied in the cemented carbide by regarding the area ratio as continuing also in a direction of depth of the cut plane, and the atomic ratio of the composite carbonitride contained in the core portion (ba) is identified by analyzing a cut plane obtained by cutting the cemented carbide along an arbitrary plane with an energy dispersive X-ray spectroscope attached to the scanning electron microscope. first hard-phase particles (a) containing WC; second hard-phase particles (b) which contain carbonitride containing at least Ti and Nb; and a metallic binder phase (c) containing an iron-group element, the second hard-phase particle (b) including a granular core portion (ba) and a peripheral portion (bb) which covers at least a part of the core portion (ba), the core portion (ba) containing composite carbonitride expressed as Ti 1-X-Y Nb X W Y C 1-Z N Z, where X is 0.1 or more and 0.2 or less, Y is 0 or more and 0.05 or less, and Z is 0.3 or more and 0.6 or less, the peripheral portion (bb) being different in composition from the core portion (ba), the content of WC in the first hard-phase particles is 99% by mass or more, the metallic binder phase is composed of not less than 90 atomic % Co, wherein in the core portion, optionally a total amount of V, Cr, and Mo occupied in a total amount of Ti, Nb, W, V, Cr, and Mo is smaller than 2 atomic %, characterised in that, the cemented carbide having an absolute value of a difference not greater than 10, between a ratio ( %) of an area occupied by the second hard-phase particles at a surface of the cemented carbide and a ratio ( %) of an area occupied by the second hard-phase particles in a region extending from the surface by 0.5 mm in a direction of depth, wherein the ratio ( %) of the area occupied by second hard-phase particles at the surface of the cemented carbide and the ratio ( %) of the area occupied by the second hard-phase particles in the region extending from the surface by 0.5 mm in the direction of depth are determined by the method described in the description, a volume ratio of the core portion (ba) in the cemented carbide is not lower than 2 volume % and not higher than 20 volume %, the volume ratio of the core portion (ba) occupied in cemented carbide is found by a method in which an area ratio of the core portion (ba) in an observation field of view is found by preparing and observing the cut plane with a SEM at a magnification of from 3000 to 5000x, and analyzing an image with image analysis software, then the area ratio is regarded as a volume ratio of the core portion (ba) occupied in the cemented carbide by regarding the area ratio as continuing also in a direction of depth of the cut plane, and the atomic ratio of the composite carbonitride contained in the core portion (ba) is identified by analyzing a cut plane obtained by cutting the cemented carbide along an arbitrary plane with an energy dispersive X-ray spectroscope attached to the scanning electron microscope.