An intradermal injection device, comprising: - a housing; - a foot mounted to the housing, and having a surface which can be placed on a subject's skin to be injected, and having an opening for allowing passage of a needle; - a reservoir movably mounted in the housing, and having a hollow space for holding a fluid to be administered to the subject; - a hollow needle movably mounted in the housing such that it can selectively protrude through the opening or be retracted from the opening, and having a first end for penetrating the subject's skin and a second end for penetrating the reservoir, the first end having a first opening for administering the fluid to the subject, the second end having a second opening for accepting the fluid from the reservoir and passing it through the needle to the first end; - a plunger movably mounted in the housing for moving the needle through the opening for penetrating the subject's skin, and for pressing the fluid out of the reservoir into the needle; - the reservoir is frictionally mounted inside the housing by first friction means (510, 308), and the plunger is frictionally mounted to the reservoir by second friction means (307, 605, α33) in such a way that the force required to overcome the resistance to move the plunger with respect to the reservoir is at least a predetermined amount larger than the force required to overcome the friction to move the reservoir with respect to the housing; wherein - the intradermal injection device furthermore comprises safety locking means (605, 313, 308, 518, 509) comprising a spring for automatically withdrawing the needle back into the opening when pressure on the plunger is released and the device is in an unlocked mode where axial movement of the plunger is allowed, and for blocking the needle after being withdrawn, wherein the reservoir has a dividing wall forming a bottom of a hollow space for holding the fluid, and wherein the plunger has a plunger head with a shape complementary to the shape of the dividing wall; characterised in that the device further comprises means for rotating the foot over a predefined angle, with respect to the longitudinal axis, for bringing the device in the unlocked mode. - a housing; - a foot mounted to the housing, and having a surface which can be placed on a subject's skin to be injected, and having an opening for allowing passage of a needle; - a reservoir movably mounted in the housing, and having a hollow space for holding a fluid to be administered to the subject; - a hollow needle movably mounted in the housing such that it can selectively protrude through the opening or be retracted from the opening, and having a first end for penetrating the subject's skin and a second end for penetrating the reservoir, the first end having a first opening for administering the fluid to the subject, the second end having a second opening for accepting the fluid from the reservoir and passing it through the needle to the first end; - a plunger movably mounted in the housing for moving the needle through the opening for penetrating the subject's skin, and for pressing the fluid out of the reservoir into the needle; - the reservoir is frictionally mounted inside the housing by first friction means (510, 308), and the plunger is frictionally mounted to the reservoir by second friction means (307, 605, α33) in such a way that the force required to overcome the resistance to move the plunger with respect to the reservoir is at least a predetermined amount larger than the force required to overcome the friction to move the reservoir with respect to the housing; wherein - the intradermal injection device furthermore comprises safety locking means (605, 313, 308, 518, 509) comprising a spring for automatically withdrawing the needle back into the opening when pressure on the plunger is released and the device is in an unlocked mode where axial movement of the plunger is allowed, and for blocking the needle after being withdrawn,