A locking device having a housing installed in a stationary manner in or at a leaf. The locking device has a locking element that is movable translationally into and out of the housing and has at least a first actuating device including a handle piece accessible from outside the housing that is operatively connected to the locking element such that the locking element is moved when this handle piece is moved along a predetermined movement path. The locking device has a second actuating device received in the housing that includes a transmission device which can be rotationally actuated and turned or rotated by a turning part. The turning part is accessible from outside the housing and is operatively connected to the locking element so that the locking element is moved out of the housing by turning the turning part in a locking direction.