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 0.6 or less, Y is 0 or more and 0.05 or less, and Z is 0.3 or more and 0.6 or less, and the peripheral portion (bb) being different in composition from the core portion (ba), and the peripheral portion (bb) being composed to be higher in content of W than 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 ; a volume ratio of the core portion in the cemented carbide is not lower than 2 volume % and not higher than 20 volume %, wherein 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. 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 0.6 or less, Y is 0 or more and 0.05 or less, and Z is 0.3 or more and 0.6 or less, and the peripheral portion (bb) being different in composition from the core portion (ba), and the peripheral portion (bb) being composed to be higher in content of W than 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 ; a volume ratio of the core portion in the cemented carbide is not lower than 2 volume % and not higher than 20 volume %, wherein 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. <EOS>