The invention relates to an inserter device for subcutaneously inserting a medical device, the inserter device comprising an outer part comprising one or more locking elements including a first locking element and one or more release elements including a first release element； a housing； and a functional part accommodated in the housing； wherein the housing comprises a sidewall with an inner surface forming a cavity, the housing extending from a first end to a second end along a first axis and comprising one or more housing guide members including a first housing guide member for engagement with one or more guide members of the functional part, and where the housing is at least partly covered by the outer part； wherein the functional part comprises a first part with a first body extending from a first end to a second end along the first axis, the first part comprising one or more first locking members； a second part releasably connected to the first part and comprising a second body extending from a first end to a second end along the first axis, the second part comprising a second guide member and one or more second locking members； an insertion needle attached to the second part； an insertion spring adapted for moving the first part from a first position to a second position in an insertion direction along the first axis in relation to the housing； and a retraction spring adapted for moving the second part from the second position to a third position in an extraction direction along the first axis in relation to the housing.
