A releasing structure for a lancing device, comprising: a lancet body with a lancet at the front; a lancet holder mounted with the lancet body with the lancet at the front; a stem disposed behind the lancet holder and moving the lancet holder forward/backward; a rotary housing pushing/pulling the stem while turning forward at a predetermined angle about a rotational axis defined in the movement direction of the lancet; a torsion spring storing torque for turning the rotary housing forward at a predetermined angle; and a loading handle transmitting torque to the torsion spring while turning forward at a predetermined angle, characterized in that one end of the stem is connected to the lancet holder by a connection pin and the other end is inserted in the rotary housing, a disc formed radially from the rotation center axis of the stem in the rotary housing is formed on the portion of the stem which is inserted in the rotary housing, a forward-inclined rib (520a, 520b) inclined within a predetermined range of anglein the rotation direction is formed on the rear side of the disc (550 and a backward-inclined rib (530a, 530b corresponding to the forward-inclined ribs (520a, 520b) is formed on the front side of the disc, a forward rib protrudes at a side on the inner side of the rotary housing with the stem inserted, corresponding to the forward-inclined rib(520a, 520b), and pushes the stem forward by moving along the inclined surface of the forward-inclined rib (520a, 520b) while turning with the rotary housing, and a backward rib protrudes at the other side on the inner side of the rotary housing, corresponding to the backward-inclined rib, and pushes the stem backward by moving along the inclined surface of the backward-inclined rib (530a, 530b) while turning with the rotary housing. a lancet body with a lancet at the front; a lancet holder mounted with the lancet body with the lancet at the front; a stem disposed behind the lancet holder and moving the lancet holder forward/backward; a rotary housing pushing/pulling the stem while turning forward at a predetermined angle about a rotational axis defined in the movement direction of the lancet; a torsion spring storing torque for turning the rotary housing forward at a predetermined angle; and a loading handle transmitting torque to the torsion spring while turning forward at a predetermined angle, characterized in that one end of the stem is connected to the lancet holder by a connection pin and the other end is inserted in the rotary housing, a disc formed radially from the rotation center axis of the stem in the rotary housing is formed on the portion of the stem which is inserted in the rotary housing, a forward-inclined rib (520a, 520b) inclined within a predetermined range of anglein the rotation direction is formed on the rear side of the disc (550 and a backward-inclined rib (530a, 530b corresponding to the forward-inclined ribs (520a, 520b) is formed on the front side of the disc, a forward rib protrudes at a side on the inner side of the rotary housing with the stem inserted, corresponding to the forward-inclined rib(520a, 520b), and pushes the stem forward by moving along the inclined surface of the forward-inclined rib (520a, 520b) while turning with the rotary housing, and a backward rib protrudes at the other side on the inner side of the rotary housing, corresponding to the backward-inclined rib, and pushes the stem backward by moving along the inclined surface of the backward-inclined rib (530a, 530b) while turning with the rotary housing.