A cutting tool comprising a cutting edge member which forms at least one corner part, wherein: a material for the cutting edge member is selected from diamond, an ultrahigh-pressure sintered body containing cubic boron nitride or a PVD or CVD coating applied to a surface of the ultrahigh-pressure sintered body; at least part of an intersecting edge between an end surface of the cutting edge member and a peripheral side surface thereof is provided with a cutting edge; a chip breaker comprising a breaker wall surface is formed in the end surface of the cutting edge member; the breaker wall surface has at least one projected surface part; and as viewed from the end surface of the cutting edge member, the projected surface part is arranged so as to be apart from a virtual plane which is defined so as to divide the corner part into halves, wherein: the breaker wall surface has at least one recessed surface part; and the recessed surface part is arranged so as to intersect with the virtual plane, wherein the breaker wall surface is formed in a shape of plane symmetry to the virtual plane, characterised in that: the at least one projected surface part is curved so as to bulge outward from the cutting tool, and the at least one recessed surface part is curved so as to be dented inward of the cutting tool, wherein in a plan view, a contour shape of the projected surface part located on an upper boundary of the breaker wall surface is a substantially circular arc shape, and a contour shape of the recessed surface part located on an upper boundary of the breaker wall surface is a substantially circular arc shape, and wherein when defining, as viewed from the end surface, a point on the upper boundary of the breaker wall surface where the projected surface part is furthest projected as a projected point D, and when defining, as viewed from the end surface, a length, in a direction parallel to the virtual plane, which ranges from a center of the corner part to the projected point D, as a breaker width B, and when defining, as viewed from the end surface, a distance from the virtual plane to the projected point D as an amount of shifting C, the amount of shifting C is from 50% to 150% with respect to the breaker width B. a material for the cutting edge member is selected from diamond, an ultrahigh-pressure sintered body containing cubic boron nitride or a PVD or CVD coating applied to a surface of the ultrahigh-pressure sintered body; at least part of an intersecting edge between an end surface of the cutting edge member and a peripheral side surface thereof is provided with a cutting edge; a chip breaker comprising a breaker wall surface is formed in the end surface of the cutting edge member; the breaker wall surface has at least one projected surface part; and as viewed from the end surface of the cutting edge member, the projected surface part is arranged so as to be apart from a virtual plane which is defined so as to divide the corner part into halves, wherein: the breaker wall surface has at least one recessed surface part; and the recessed surface part is arranged so as to intersect with the virtual plane, wherein the breaker wall surface is formed in a shape of plane symmetry to the virtual plane, characterised in that: the at least one projected surface part is curved so as to bulge outward from the cutting tool, and the at least one recessed surface part is curved so as to be dented inward of the cutting tool, the breaker wall surface has at least one recessed surface part; and the recessed surface part is arranged so as to intersect with the virtual plane, wherein the breaker wall surface is formed in a shape of plane symmetry to the virtual plane, the at least one projected surface part is curved so as to bulge outward from the cutting tool, and the at least one recessed surface part is curved so as to be dented inward of the cutting tool, wherein in a plan view, a contour shape of the projected surface part located on an upper boundary of the breaker wall surface is a substantially circular arc shape, and a contour shape of the recessed surface part located on an upper boundary of the breaker wall surface is a substantially circular arc shape, and wherein when defining, as viewed from the end surface, a point on the upper boundary of the breaker wall surface where the projected surface part is furthest projected as a projected point D, and when defining, as viewed from the end surface, a length, in a direction parallel to the virtual plane, which ranges from a center of the corner part to the projected point D, as a breaker width B, and when defining, as viewed from the end surface, a distance from the virtual plane to the projected point D as an amount of shifting C, the amount of shifting C is from 50% to 150% with respect to the breaker width B.