A spark plug includes: a center electrode having at least one first spark surface and extending along a longitudinal axis of the spark plug; and a ground electrode having at least one second spark surface, the first spark surface being situated diametrically opposed to the second spark surface, so that an ignition spark may be generated between the first and second spark surfaces, the center electrode being rotatable coaxially to the longitudinal axis with respect to the ground electrode, and the first and second spark surfaces being inclined in such a way that rotating the center electrode with respect to the ground electrode makes it possible to set a distance between the first and second spark surfaces.