An injector for injecting pellets includes a main body, a delivery opening which is formed on the main body and to which a hollow-bore needle can be connected and a magazine guide formed in the main body for a magazine which, for accommodating the pellets, comprises several barrels. Each barrel includes a hollow cylindrical compartment with an open front end and an open rear end. The magazine guide brings the magazine, barrel by barrel, into an injection position, in which a plunger of the injector can be introduced into the barrel via the rear end of the barrel positioned in the injection position and moved in the direction of the delivery opening in order to deliver the pellet provided in the barrel via the delivery opening. A drawer is formed in the main body for accommodating a replacement hollow-bore needle.