To provide a device for an optical detection of a tissue contact.

An electrosurgical device comprises a surface-contact detection device. The surface-contact detection device includes: a lens member; at least one optical transmitter 275 to generate optical signals; and at least one optical receiver 277 to receive optical signals reflected by the lens member. The lens member is adapted to allow the at least one optical transmitter 275 and the at least one optical receiver 277 to communicate when the lens member is disposed in contact with tissue T.