An inserter for an intrauterine system, comprising - a handle (3) provided with a longitudinal opening (8) at its first end, said opening (8) having a longitudinal axis parallel to the longitudinal axis of the inserter, a first end (8a) and a second end (8b), - a mobile slide (5) disposed in said longitudinal opening (8) and provided with a first end (5a) and a second end (5b), - a mobile plunger (2), - a insertion tube (6) arranged around the plunger (2) and provided with a first end and a second end, with its second end fixed to the slide (5), - a blocking means for reversibly blocking the intrauterine system in relation to the plunger (2) through a withdrawal cord of the intrauterine system, said locking means being fixed to the plunger and being controllable at least by a part or an extension of said slide (5) and / or the insertion tube (6) or of the handle (3), characterized in that the inserter comprises, ad in addition, a movement means (18) comprising a rotation part (19) arranged to rotate about a rotation axis that is perpendicular to the longitudinal axis of the inserter, the rotation part (19) being arranged in functional connection with the piston (2) and with the slide (5) in such a way that the movement of the slide (5) generates a simultaneous movement of the piston (2) and the insertion tube (6) along the longitudinal axis of the inserter, in opposite directions.Un insertador para un sistema intrauterino, que comprende - un mango (3) dotado de una abertura longitudinal (8) en su primer extremo, teniendo dicha abertura (8) un eje longitudinal paralelo al eje longitudinal del insertador, un primer extremo (8a) y un segundo extremo (8b), - una corredera móvil (5) dispuesta en dicha abertura longitudinal (8) y dotada de un primer extremo (5a) y un segundo extremo (5b), - un émbolo móvil (2), - un tubo de inserción (6) dispuesto alrededor del émbolo (2) y dotado de un primer extremo y un segundo extremo, con su segundo extremo fijado a la corredera (5),
