Abstract: The invention relates to a bipolar ESD protection comprising a protection transistor with a short-circuited base emitter (18, 19). Due to the snap-back effect, the transistor can switch from the normal high-ohmic condition to a low-ohmic condition in the case of ESD. To improve the protection performance, the protection structure is provided with a trigger element comprising a second transistor (26, 27, 28) with a lower breakdown voltage. The base (26) and the emitter (28) of the second transistor are connected to the base of the protection transistor. To increase the current carrying capability of the protection device, the trigger transistor is designed so as to be a vertical transistor.