Passive leaf locking device for a door, a window or similar, having a frame that can be mounted in a stationary manner having at least one active leaf attached in the frame - referred to below as the active leaf - and at least one passive leaf - referred to below as the passive leaf, wherein the passive leaf locking device can be mounted in or on the passive leaf and has a locking mechanism and a lock actuation device, and wherein the passive leaf locking device has a latch lifting device and/or a bolt lifting device, wherein it is provided that the locking mechanism of the passive leaf locking device has an upper locking rod connection device of an upper locking rod guided in and/or on the passive leaf, said locking rod being able to be extended upwards for locking and being able to be retracted downwards for unlocking, and/or the locking mechanism of the passive leaf locking device has a lower locking rod connection device of a lower locking rod guided in and/or on the passive leaf, said locking rod being able to be extended downwards for locking and being able to be retracted upwards for unlocking, characterised in that a) the passive leaf locking device has a sensor device in order to detect whether or not a latch, namely a locking latch or latch bolt of an active leaf locking device mounted in or on the active leaf, engages in a predetermined space of the passive leaf locking device, wherein the latch lifting device has the sensor device in order to detect whether or not the latch of the active leaf locking device engages in a predetermined space of the passive leaf locking device, wherein the sensor device enables control and monitoring of the lifting device of the latch in the region of the latch lifting device, and wherein the sensor device is formed in such a way that it outputs electrical signals to an electrical signal processing device depending on the result of this detection; and/or b) the passive leaf locking device has a sensor device in order to detect whether or not a bolt of an active leaf locking device mounted in or on the active leaf engages in a predetermined space of the passive leaf locking device, wherein the bolt lifting device has the sensor device in order to detect whether or not the bolt of the active leaf locking device engages in a predetermined space of the passive leaf locking device, wherein the sensor device enables control and monitoring of the lifting device of the bolt in the region of the bolt lifting device, and wherein the sensor device is formed in such a way that it outputs electrical signals to an electrical signal processing device depending on the result of this detection. a) the passive leaf locking device has a sensor device in order to detect whether or not a latch, namely a locking latch or latch bolt of an active leaf locking device mounted in or on the active leaf, engages in a predetermined space of the passive leaf locking device, wherein the latch lifting device has the sensor device in order to detect whether or not the latch of the active leaf locking device engages in a predetermined space of the passive leaf locking device, wherein the sensor device enables control and monitoring of the lifting device of the latch in the region of the latch lifting device, and wherein the sensor device is formed in such a way that it outputs electrical signals to an electrical signal processing device depending on the result of this detection; and/or b) the passive leaf locking device has a sensor device in order to detect whether or not a bolt of an active leaf locking device mounted in or on the active leaf engages in a predetermined space of the passive leaf locking device,