The invention relates to an adhesive pad and a surface plate which in combination can provide a medical device which is to be placed on the skin of a patient. The combined medical device is provided with a subcutaneous part which necessitates that the device is securely and comfortably attached to the patient's skin. Often such devices are used to transfer medication such as insulin to a patient from a reservoir. An embodiment according to the invention relates to a medical device comprising—a cannula (22) or another part to be positioned subcutaneously when in use,—a surface plate (1) provided with a contact surface and with an opening (12B) through which the cannula (22) or another subcutaneously positioned part passes when the medical device is in use, and—an adhesive pad (2) secured to the contact surface of the surface plate (1) providing adhesion of the surface plate (1) to a skin surface which adhesive pad (2) comprises—a first surface facing the contact surface and having areas unreleasably secured to the contact surface by welding, and—a second surface facing the skin of a patient during use and having areas provided with a skin compatible adhesive which can be releasably secured to the skin of a patient wherein an adhesive part (30) has been placed between the contact surface of the surface plate (1) and the first surface of the adhesive pad (2) in an area where the two surfaces have not been welded together thereby securing these unwelded areas of the contact surface to the first surface.