There is provided a cemented carbide comprising a hard phase component which comprises a tungsten carbide (WC) and at least one selected from carbides, nitrides and carbonitrides of metals of the groups 4a, 5a and 6a in the periodic table; and a binder phase component comprising at least one of iron-group metals, wherein the surface region of the cemented carbide has 90-98% of the minimum hardness as compared with internal hardness, thereby having high hardness and toughness which is suitable to using as a cutting tool.