Easily serviced and hygienically maintained liquid supply system. A liquid storage vessel switching device switches between vessels to supply liquid uninterruptedly. Provided in a first connection tube is a liquid cutoff device, including a loop section, for switching the system between allowing/cutting-off supplying of liquid to a dispenser through the first connection tube. Utilizing the liquid cutoff device eliminates, along the first connection tube, intervening conventional valves having structural components that come in direct contact with the supplied liquid, and on which sponges or other cleaning elements might get caught. The inner wall of the first connection tube may thus be cleaned readily with a sponge or the like. Beverages such as beer thus can easily be kept hygienically and served.