An insertion device with an underside for placing on the skin of a patient, which has a recess for an insertion needle. The insertion device has means for forming a skin surface rising like a step or slope and facing towards the recess, preferably bearing on the recess. The means for forming the step or slope may include first and second pressure areas for pressing the skin with the recess for the needle located between the first and second pressure areas. The device may be configured whereby a downwardly extending cutting plane, in which the insertion needle lies, intersects the first pressure area in a first line and the second pressure area in a second line, and wherein the first line in the vicinity of the recess extends at a greater height than the second line. At least one of the two pressure areas may be a strip.