A catheter (10) having an internal tube (13) and an external tube (14) which at least sectionally encloses the internal tube (13). The external tube (14) is connected to a balloon (16) having an endoprosthesis section (18) which positions an intraluminal endoprosthesis (20). The catheter (10) has stiffening means (31, 33, 34, 35) located in the area of at least one end of the endoprosthesis section (18) in its longitudinal direction on the internal tube (13). Also disclosed is a system comprising an intraluminal endoprosthesis (20) and a catheter (10) used for introducing an intraluminal endoprosthesis (20), preferably a stent, into a body cavity.