The invention pertains to a kit for assembling a disposable applicator for inserting an implant, in particular a rod-like implant containing an active substance, under the skin of a human or animal, the kit comprising a first component, in turn comprising a main housing part providing a handle for grasping and maneuvering the applicator, a cannula, and a cannula holder mounted in the main housing part, the main housing part having an opening which allows introduction of an implant into the proximal end of the cannula or the cannula holder, and, a second component for closing said opening, in turn comprising a second housing part and a rod attached to or forming an integral whole with the second housing part and mountable inside the cannula or the cannula holder.