A clasp comprising a male member that comprises an insertion portion consisting of a columnar body, and comprising a female member that comprises a housing portion having a cylindrical shape and comprising an opening at one end, the housing portion being arranged to house the columnar body when the columnar body is inserted thereinto in an axial direction, wherein the insertion portion and the housing portion each comprise attraction members (25, 45) arranged to attract the insertion portion into the housing portion by magnetic attraction force, wherein the male member comprises a male engagement body on an outer peripheral surface of the insertion portion, wherein the female member comprises a female engagement body on an inner peripheral surface of the housing portion, wherein either the male engagement body is a protruding engagement body comprising one of a pin and a protrusion erected from the outer peripheral surface of the insertion portion while the female engagement body is a combination of a longitudinal engagement body and a retaining portion, the longitudinal engagement body comprising a guiding portion (72, 73) mounted on a mounting surface which is the inner peripheral surface of the housing portion, or the female engagement body is a protruding engagement body comprising one of a pin and a protrusion erected from the inner peripheral surface of the housing portion while the male engagement body is a combination of a longitudinal engagement body and a retaining portion, the longitudinal engagement body comprising a guiding portion (72, 73) mounted on a mounting surface which is the outer peripheral surface of the insertion portion, wherein the longitudinal engagement body has one of an edge structure protruding from the mounting surface and a notch structure recessed from the mounting surface, and the longitudinal engagement body has a size in a longitudinal direction along an axis of one of the insertion portion and the housing portion that is larger than one of a protruding height of the edge structure and a recessed depth of the notch structure, wherein the protruding engagement body and the retaining portion are capable of preventing, by being locked to each other, the insertion portion from getting out of the housing portion in the axial direction when the insertion portion and the housing portion are in a specified placement where the insertion portion is inserted into the housing portion at a predetermined rotation angle up to a predetermined depth, characterized in that the guiding portion (72, 73) is formed as an end edge of the longitudinal engagement body that is inclined with respect to the axis of one of the insertion portion and the housing portion, and is arranged to guide the protruding engagement body when the protruding engagement body is brought into contact with the guiding portion (72, 73) to a position corresponding to the specified placement from both directions of a clockwise direction and a counterclockwise direction with respect to the axis of the one of the insertion portion and the housing portion in the presence of the magnetic attraction force by the attraction members (25, 45). the male engagement body is a protruding engagement body comprising one of a pin and a protrusion erected from the outer peripheral surface of the insertion portion while the female engagement body is a combination of a longitudinal engagement body and a retaining portion, the longitudinal engagement body comprising a guiding portion (72, 73) mounted on a mounting surface which is the inner peripheral surface of the housing portion, or the female engagement body is a protruding engagement body comprising one of a pin and a protrusion erected from the inner peripheral surface of the housing portion while the male engagement body is a combination of a longitudinal engagement body and a retaining portion, the longitudinal engagement body comprising a guiding portion (72, 73) mounted on a mounting surface which is the outer peripheral surface of the insertion portion,