A connection device for a catheter, especially for a peripheral venous catheter, comprisinga) a main body (1) having a main body infusion channel (2), the main body with a through-flow element (3, 103, 203), having sterilizing effect and forming at least a part of the main body infusion channel (2, 102), and with a coupling element (6), wherein the main body (1) is in one piece, andb) an attachment body (8) having an attachment body infusion channel (7), wherein the attachment body (8) and the coupling element (6) have means to detachably fix the attachment body (8) to the coupling element (6),is characterized in thatc) the main body (1) comprises massive material having a sterilizing effect, wherein the massive material is uncoated at least on walls provided for contacting with infusion liquid andd) the massive material comprises a matrix made of at least one first material, wherein at least one further material having a sterilizing effect is incorporated into the matrix.
