An injection device for injecting a liquid drug, comprising: a housing assembly (10, 20;110, 120) supporting a non-removable cartridge (5;105) having an interior chamber containing a liquid drug to be injected, a needle cannula (30; 130) connected to the cartridge (5;105) and having a distal tip (33;133) for penetrating the skin (S) of a user and a longitudinal lumen (34;134), a needle shield assembly (40, 40A, 40B, 60; 140, 140A, 140B) which is provided with a cleaning chamber (51;151) containing a volume of a cleaning agent for cleaning at least the distal tip (33;133) of the needle cannula (30;130) between subsequent injections, wherein the needle shield assembly (40, 40A, 40B, 60;140, 140A, 140B) is movable in a proximal direction in relation to the housing assembly (10, 20;110, 120) from a first position to a second position, wherein; - the first position is a position in which the distal tip (33;133) of the needle cannula (30;130) is located inside the cleaning chamber (51;151), - the second position is a position in which the distal tip (33;133) of the needle cannula (30;130) is located outside and distal to the cleaning chamber (51;151) for equalizing the pressure in the cartridge (5;105), and wherein the needle shield assembly (40, 40A, 40B, 60;140, 140A, 140B) moves from the first position to the second position upon rotation of at least one part of the needle shield assembly (40, 40A, 40B, 60; 140, 140A, 140B). a housing assembly (10, 20;110, 120) supporting a non-removable cartridge (5;105) having an interior chamber containing a liquid drug to be injected, a needle cannula (30; 130) connected to the cartridge (5;105) and having a distal tip (33;133) for penetrating the skin (S) of a user and a longitudinal lumen (34;134), a needle shield assembly (40, 40A, 40B, 60; 140, 140A, 140B) which is provided with a cleaning chamber (51;151) containing a volume of a cleaning agent for cleaning at least the distal tip (33;133) of the needle cannula (30;130) between subsequent injections, wherein the needle shield assembly (40, 40A, 40B, 60;140, 140A, 140B) is movable in a proximal direction in relation to the housing assembly (10, 20;110, 120) from a first position to a second position, wherein; - the first position is a position in which the distal tip (33;133) of the needle cannula (30;130) is located inside the cleaning chamber (51;151), - the second position is a position in which the distal tip (33;133) of the needle cannula (30;130) is located outside and distal to the cleaning chamber (51;151) for equalizing the pressure in the cartridge (5;105), - the first position is a position in which the distal tip (33;133) of the needle cannula (30;130) is located inside the cleaning chamber (51;151), - the second position is a position in which the distal tip (33;133) of the needle cannula (30;130) is located outside and distal to the cleaning chamber (51;151) for equalizing the pressure in the cartridge (5;105), and wherein the needle shield assembly (40, 40A, 40B, 60;140, 140A, 140B) moves from the first position to the second position upon rotation of at least one part of the needle shield assembly (40, 40A, 40B, 60; 140, 140A, 140B). <EOS>