the present invention relates to a medicament delivery device comprising a housing (10), which housing (10) is arranged ranged to accommodate a medicament container (16), the device further comprises a drive mechanism (18) capable of, upon activation, expel a dose of medicament from said medicament container, the drive mechanism comprising a flat spiral spring (26). The invention is characterised in that at least a part (36) of an outermost turn of said flat spiral spring (26) is positioned on an outer surface of said housing (10).
