A beverage dispenser includes a beverage container assembly combined by two single chamber containers, in which each single chamber container has an internal chamber and a predetermined access opening on a top, whereby the access openings are concealed and enclosed by a top closure cap assembly. The top closure cap assembly provides each single chamber container with a spout opening and at least one air holes. The top closure cap assembly further installed with at least one air tight shut off device for selectively shutting off at least one spout opening and one air hole. Whereby the improved beverage dispenser has relatively simple and low cost structure for enabling the user to selectively serve two kinds of beverage received within the two single chamber containers respectively at a time by a single hand operation for bringing great conveniences for standard households or businesses.