An injector device for transcutaneously placing a hollow cannula of a subcutaneous infusion set is disclosed. The injector device includes a plunger slidably received within the device housing for movement between an advanced position and a retracted position, the plunger having an insertion needle secured thereto by a stable connection preventing loss of the insertion needle during use of the device. The insertion needle receives and supports the cannula of the subcutaneous infusion set in a position with the cannula oriented for transcutaneous placement upon movement of the plunger from the retracted position to the retracted position.