A dresser (3, 13, 23, 33, 43, 53, 63) comprising: a mount component (8, 18, 28, 38, 48, 58, 68); and a cutting edge component (1, 11, 21, 31, 41, 51, 61) inserted in the mount component (8, 18, 28, 38, 48, 58, 68) at a base end portion side, the cutting edge component (1, 11, 21, 31, 41, 51, 61) including a portion inserted in the mount component (8, 18, 28, 38, 48, 58, 68) and an exposed portion exposed from the mount component (8, 18, 28, 38, 48, 58, 68), the cutting edge component (1, 11, 21, 31, 41, 51, 61) being fixed to the mount component (8, 18, 28, 38, 48, 58, 68) by bringing, into contact with the mount component (8, 18, 28, 38, 48, 58, 68), the portion of the cutting edge component (1, 11, 21, 31, 41, 51, 61) inserted in the mount component (8, 18, 28, 38, 48, 58, 68), the cutting edge component (1, 11, 21, 31, 41, 51, 61) being exposed from the mount component (8, 18, 28, 38, 48, 58, 68) at a front end portion side to form a cutting edge, wherein the portion of the cutting edge component (1, 11, 21, 31, 41, 51, 61) inserted in the mount component (8, 18, 28, 38, 48, 58, 68) has one or more portions in each of which an area of a cross section along a line normal to an insertion direction of the cutting edge component (1, 11, 21, 31, 41, 51, 61) is increased from the front end portion side toward the base end portion side in the insertion direction, and a ratio L1/M1 of a length L1 and a maximum value M1 is more than or equal to 2.1, where L1 represents a length of the portion of the cutting edge component (1, 11, 21, 31, 41, 51, 61) inserted in the mount component (8, 18, 28, 38, 48, 58, 68) and M1 represents a maximum value of a diameter of a circle having an area equal to the area of the cross section along the line normal to the insertion direction in the portion of the cutting edge component (1, 11, 21, 31, 41, 51, 61) inserted in the mount component (8, 18, 28, 38, 48, 58, 68). a mount component (8, 18, 28, 38, 48, 58, 68); and a cutting edge component (1, 11, 21, 31, 41, 51, 61) inserted in the mount component (8, 18, 28, 38, 48, 58, 68) at a base end portion side, the cutting edge component (1, 11, 21, 31, 41, 51, 61) including a portion inserted in the mount component (8, 18, 28, 38, 48, 58, 68) and an exposed portion exposed from the mount component (8, 18, 28, 38, 48, 58, 68), the cutting edge component (1, 11, 21, 31, 41, 51, 61) being fixed to the mount component (8, 18, 28, 38, 48, 58, 68) by bringing, into contact with the mount component (8, 18, 28, 38, 48, 58, 68), the portion of the cutting edge component (1, 11, 21, 31, 41, 51, 61) inserted in the mount component (8, 18, 28, 38, 48, 58, 68), the cutting edge component (1, 11, 21, 31, 41, 51, 61) being exposed from the mount component (8, 18, 28, 38, 48, 58, 68) at a front end portion side to form a cutting edge, wherein the portion of the cutting edge component (1, 11, 21, 31, 41, 51, 61) inserted in the mount component (8, 18, 28, 38, 48, 58, 68) has one or more portions in each of which an area of a cross section along a line normal to an insertion direction of the cutting edge component (1, 11, 21, 31, 41, 51, 61) is increased from the front end portion side toward the base end portion side in the insertion direction, and a ratio L1/M1 of a length L1 and a maximum value M1 is more than or equal to 2.1, where L1 represents a length of the portion of the cutting edge component (1, 11, 21, 31, 41, 51, 61) inserted in the mount component (8, 18, 28, 38, 48, 58, 68) and M1 represents a maximum value of a diameter of a circle having an area equal to the area of the cross section along the line normal to the insertion direction in the portion of the cutting edge component (1, 11, 21, 31, 41, 51, 61) inserted in the mount component (8, 18, 28, 38, 48, 58, 68).