Medicament injection apparatus includes: main body, is configured to receive with the drug cartridge of first transparent spacer sealing Cap assembly comprising button cap and carrier element, the button cap is rotatable relative to carrier element, and is wherein aligned if button is not rotated into relative to the carrier element, and the button cap is prevented from axially displaced in a proximal direction Needle stand, it is connected to carrier element in a manner of releasable, the needle stand carries needle, the needle set has proximally and distally, and the needle stand is connected to button in a manner of releasable, wherein, after the button cap is relative to the rotary alignment of the carrier element, the button cap can shift in the proximal direction along axial direction, wherein the button cap causes the needle stand to shift in the proximal direction along axial direction in the axial displacement in the proximal direction And wherein, after button cap axial displacement in a proximal direction, the cap assembly can be separated from the main body along distal direction.
