The aim of the invention is to provide a reliably functioning lock for a motor vehicle in particular. This is achieved in that the claimed lock for a door or a panel has a locking mechanism consisting of a rotary latch and at least one pawl for locking the rotary latch. The rotary latch and the pawl are preferably designed such that the rotary latch is capable of introducing an opening torque into the pawl. The locking mechanism has a triggering lever for opening the locking mechanism. A transmission device is further provided which increases the pivotal movement of the triggering lever and which comprises a transmission lever in particular for moving the pawl out of the locking position of the pawl by means of a follower. On the basis of the pivotal movement transmission caused by the transmission lever, a relatively small pivotal movement of the triggering lever is sufficient to move the pawl completely out of the locking position by means of the follower. The invention thus ensures that a locking mechanism can be reliably opened even when the triggering lever can no longer be pivoted over the entire original distance due to the effects of aging.