A universal connector socket (7) for a surgical apparatus is suggested for the connection of different plug connectors (9, 9, 10, 12) of different surgical instruments for RF surgery, said universal connector socket having several plug contact openings (7a, 7b, 7c, 7d, 7E) for receiving the contact pins (9a, 9a, 9b, 9b, 9c, 9c, 10a, 10b, 12a, 12b) of a plug connector (9, 9, 10, 12). The universal connector socket (7) is characterized in that, for selectively connecting monopolar and bipolar surgical instruments, several plug contact openings (7a, 7b, 7c, 7d) are arranged in an overlapping manner, and that, for defining an unambiguous plug-in position of a plug connector (9, 9, 10, 12,), a shared reference plug contact opening (7E) for different plug connectors is provided, said reference plug contact opening being arranged separate from the other plug contact openings (7a, 7b, 7c, 7d).
