A vacuum pressure sensor includes a vacuum-tight electrical feedthrough. The feedthrough has an electrically insulating insulator element with a through-opening, having a first boundary surface adjacent to the through-opening and a second boundary surface also adjacent to the through-opening and opposite to the first boundary surface, and an electrically conductive conductor element which extends through the through-opening and which is connected to the insulator element in a vacuum-tight manner along a circumferential line of the conductor element. The insulator element is transmissive to electromagnetic radiation in an optical wavelength range and the first boundary surface and/or the second boundary surface is formed as a curved surface.