The invention relates to a binocular telescope with two lens barrels, which for focusing comprise axially displaceable focusing means, and with a joint focusing device, wherein the focusing device comprises a housing and a rotary knob and the rotary knob is axially displaceable on the housing, wherein the rotary knob is rotatably coupled in a focusing position to a focusing gear and is rotatably coupled in a diopter balancing position to a diopter gear, wherein the rotary knob comprises a locking mechanism for fixing the rotary knob in the focusing position.