An insertion device (110) for inserting an analyte sensor (114) into a body tissue is proposed. The insertion device (110) comprises an insertion needle holder (120) and a drive mechanism (124) for linearly driving the insertion needle holder (120) in a longitudinal direction (126). The drive mechanism (124) comprises at least one actuator (132) for actuating the drive mechanism (124). The actuator (132) comprises at least one actuator arm (136, 138) which is pivotable about at least one axle (140) in order to actuate the drive mechanism (124). The insertion device (110) further comprises at least one protection against reuse including at least one locking mechanism (178). The locking mechanism (178) is adapted to at least partially prevent a back-pivoting of the actuator arm (136, 138) in a direction reversing the actuation direction once the actuator arm (136, 138) has been pivoted by at least one threshold angle.
