A fluid supply device for an endoscope, comprising: a liquid supply unit configured for supplying liquids to the endoscope a gas supply unit configured for supplying gases to the endoscope; and a control unit configured for controlling operations of the liquid supply unit and the gas supply unit, a liquid supply flow path connected to the liquid supply unit and for connection with the endoscope; a gas supply flow path connected to the gas supply unit and for connection with the endoscope; wherein the control unit comprises: a foot switch located on the floor of an operating room configured to receive control commands on the operations of the liquid supply unit and the gas supply unit from a surgeon who uses the endoscope; and a controller configured for selectively operating the liquid supply unit and the gas supply unit according to the control commands received; a bypass flow path configured for selectively connecting the liquid supply flow path and the gas supply flow path, wherein the controller is further configured for controlling operation of the bypass flow path according to the control commands, characterised in that if the bypass flow path is open, the gas in the gas supply flow path flows into the liquid supply flow path to allow the liquid in the liquid supply flow path to be removed by means of the gas, so that the liquid supply flow path is completely dried. a liquid supply unit configured for supplying liquids to the endoscope a gas supply unit configured for supplying gases to the endoscope; and a control unit configured for controlling operations of the liquid supply unit and the gas supply unit, a liquid supply flow path connected to the liquid supply unit and for connection with the endoscope; a gas supply flow path connected to the gas supply unit and for connection with the endoscope; wherein the control unit comprises: a foot switch located on the floor of an operating room configured to receive control commands on the operations of the liquid supply unit and the gas supply unit from a surgeon who uses the endoscope; and a controller configured for selectively operating the liquid supply unit and the gas supply unit according to the control commands received; a bypass flow path configured for selectively connecting the liquid supply flow path and the gas supply flow path, wherein the controller is further configured for controlling operation of the bypass flow path according to the control commands, characterised in that if the bypass flow path is open, the gas in the gas supply flow path flows into the liquid supply flow path to allow the liquid in the liquid supply flow path to be removed by means of the gas, so that the liquid supply flow path is completely dried. a foot switch located on the floor of an operating room configured to receive control commands on the operations of the liquid supply unit and the gas supply unit from a surgeon who uses the endoscope; and a controller configured for selectively operating the liquid supply unit and the gas supply unit according to the control commands received; a bypass flow path configured for selectively connecting the liquid supply flow path and the gas supply flow path, wherein the controller is further configured for controlling operation of the bypass flow path according to the control commands, characterised in that if the bypass flow path is open, the gas in the gas supply flow path flows into the liquid supply flow path to allow the liquid in the liquid supply flow path to be removed by means of the gas, so that the liquid supply flow path is completely dried.