A self-energizing disc brake includes a brake caliper held on a fixed brake carrier, an active-side and a reaction-side brake pad, which may be pressed against a brake disc, an actuating device with a self-energizing device and an adjuster device for compensating pad and/or disc wear. The self-energizing device has at least one pressure ram, in contact on the front face with the active-side pad by way of a split bearing and fixed by the end thereof facing the brake pad to a guide plate movably held in the brake carrier, designed such that the split bearing is enclosed by a seal arrangement when the self-energizing device is in a non-functioning state.