The invention relates to a release device for actuating a delivery catheter which comprises an outer casing and a mandrin which is movably arranged in the outer casing. The release device comprises an elongated handle, a fixing seat which is arranged on the handle and which is designed to fix a proximal end piece of the mandrin on the handle in a stationary manner relative to the longitudinal axis of the handle, and a guide which is formed on the handle and which is designed to receive an actuating element that is arranged on the proximal end region of the outer casing in a movable manner with respect to the longitudinal axis of the handle and with respect to the mandrin. The handle comprises an elongated base part and an adjusting part which is connected to the base part and which can be adjusted along the longitudinal axis of the base part. The adjusting part can be switched between an adjusting state in which the adjusting part is held on the base part in an axially movable manner in order to change the length of the guide and a locking state in which the adjusting part is locked on the base part at least in an axial manner.
