The present invention relates to an auto injector, e.g. a disposable auto injector, that can be safely operated for automatic injection of a dose of medication by the recipient of the medication, having a housing for accommodation of a container with at least one compartment for accommodation of a medicament to be injected and a needle mounting site for user mounting of a needle covered by a needle cap before injection, and a needle shield that is accommodated in the housing in a retracted position before mounting of the needle and that is configured to be automatically moved forward to a protruded position by a needle shield driver upon mounting of the needle and removal of the needle cap.
