A belt lock is provided and has a lock holder that is rotatably mounted on a vehicle part. A restoring spring, as a flat spiral spring, has spiral spring windings that are disposed in a single plane and are disposed between a cover and the lock holder. The spiral spring biases the lock holder into a rest position of the belt lock, and has one end supported against the lock holder and another end supported against the cover. The cover has a first radially extending extension for the outer end of the spring, and a second extension as a stop for restoring of the lock holder.