Injection device comprising: - a tubular elongated main body - a needle shield slidably arranged in said main body, - a needle shield link slidably connected to said needle shield, - an enclosure containing medicament arranged in said main body, - a needle connected to said enclosure, - a plunger operatively arranged to said enclosure for ejecting said medicament through said needle and arranged on its upper part with a first and a second set of outwardly extending stop members (130, 206), - spring means arranged with said plunger for operating said plunger, - a dose setting knob arranged with inwardly extending stop members on its inner surface which cooperate with the plunger's second set of outwardly extending stop members for holding said plunger and said spring means in a tensioned locked position, - a needle shield spring surrounding the needle shield link, characterised in that: - said injection device further comprises a first tubular member rotationally and slidably arranged inside said needle shield link, - said first tubular member comprises a number of ridges and protrusions on its outer surface and a second set of ledges arranged on the inner surface, - said ridges and protrusions (150, 152, 154) on the outer surface of said first tubular member cooperate with guide members arranged on the inner surface of said needle shield link, - said second set of ledges on the inner surface of said first tubular member cooperate with the first set of outwardly extending stop members of the plunger, wherein - said injection device further comprises a second tubular member arranged inside said body, between the dose setting knob and the first tubular member, and rotationally locked to the dose setting knob by outwardly extending, oppositely arranged claws, wherein said second tubular member is arranged with a set of descending ledges on its inner surface, wherein said set of descending ledges cooperate with the plunger's second set of outwardly extending stop members when the guide members of the needle shield link rotate the first tubular member thereby causing the plunger to slip off the second set of ledges causing the plunger to move forward causing an injection until the second set of outwardly extending members abut one of the descending ledges which is set for a certain dose. - a tubular elongated main body - a needle shield slidably arranged in said main body, - a needle shield link slidably connected to said needle shield, - an enclosure containing medicament arranged in said main body, - a needle connected to said enclosure, - a plunger operatively arranged to said enclosure for ejecting said medicament through said needle and arranged on its upper part with a first and a second set of outwardly extending stop members (130, 206), - spring means arranged with said plunger for operating said plunger, - a dose setting knob arranged with inwardly extending stop members on its inner surface which cooperate with the plunger's second set of outwardly extending stop members for holding said plunger and said spring means in a tensioned locked position, - a needle shield spring surrounding the needle shield link, - said injection device further comprises a first tubular member rotationally and slidably arranged inside said needle shield link, - said first tubular member comprises a number of ridges and protrusions on its outer surface and a second set of ledges arranged on the inner surface, - said ridges and protrusions (150, 152, 154) on the outer surface of said first tubular member cooperate with guide members arranged on the inner surface of said needle shield link, - said second set of ledges on the inner surface of said first tubular member cooperate with the first set of outwardly extending stop members of the plunger, wherein - said injection device further comprises a second tubular member arranged inside said body, between the dose setting knob and the first tubular member, and rotationally locked to the dose setting knob by outwardly extending, oppositely arranged claws, wherein said second tubular member is arranged with a set of descending ledges on its inner surface, wherein said set of descending ledges cooperate with the plunger's second set of outwardly extending stop members when the guide members of the needle shield link rotate the first tubular member thereby causing the plunger to slip off the second set of ledges causing the plunger to move forward causing an injection until the second set of outwardly extending members abut one of the descending ledges which is set for a certain dose.