A surge protector (1) has a spark gap (2) that is provided with two opposite electrodes (3), a circuit (5) for triggering the spark gap (2), and a light source connected to a protective device (13) on ground potential in order to generate a triggering light which can be delivered with the aid of at least one optical waveguide (15) of a receiver unit of the triggering circuit (5), the spark gap (2) and the triggering circuit (5) being on a high voltage potential. In order to make the surge protector (1) reliable and inexpensive, the receiver unit is provided with at least one power semiconductor component (16) that can be moved, with the aid of the triggering light, from a locked position in which current conduction via the power semiconductor component (16) is interrupted into an open position in which current conduction via the power semiconductor component (16) is made possible.