An implantable cardiac pacemaker with automatic control of the connection of a probe and the implantation of the case. The device includes a generator and its energy source. The generator includes: circuits for scanning battery consumption, able to measure current output by the battery and to deliver a measured value of the output current; comparator circuits, able to compare the current value measured with a pre-programmed value of threshold of current. It includes moreover circuits suited to: detect and count the spontaneous depolarizations collected between the aforementioned terminals of the head of connector; to compare the number of depolarizations thus counted with a pre-programmed threshold of counting; and to deliver a signal of suspicion of implantation in the event of crossing of this threshold of counting.