The invention relates to an injection device (1), which comprises a supporthousing (2), an activating sleeve (9), a cartridge (3) containing a medicine(14), afirst drive unit (4), a safety device (5), a needle arrangement (6), a needleprotectionelement (7) and a second triggerable drive unit (8), whereby the lattermoves the needle protection element (7) from the non-effective position intotheposition covering one needle end (21) of a cannula (20). The support housing(2)is surrounded over most of its longitudinal extension between its distal andproximal end (11, 12) by the activating sleeve (9), whereby the needleprotectionelement (7) with the second drive unit (8) cooperating therewith is arrangedradially between the support housing (2) and the activating sleeve (9), asviewedin axial cross section.