PURPOSE: To enable the brewing of even a small amount of coffee powder for one to two cups by using a bottom plate capable of causing a large elastic deformation for the bottom of a tank located above a conduit tube.

CONSTITUTION: Water is supplied to a vessel 31 through a water inlet 43a via a feed water pipe 37. Water in the vessel 31 is discharged from a delivery port 40b via a conduit tube 40 and air enters the vessel 31 through a water suction port 40a, thereby stopping water discharge. When water is heated with an exothermic body 34 up to the predetermined temperature, a temperature regulator 35 operates to stop a heating process. A basket 41 is filled with coffee powder and set in a brewer, and water is supplied from the water inlet 43a. The bottom of a tank 36 is located above the upper surface of the conduit tube 40 and, therefore, hot water in the vessel 31 is discharged from the delivery port 40b, even with a small amount of water supplied. The hot water is thereby poured onto the coffee powder in the basket 41, and brewed coffee drops to a decanter 42. When a large amount of water is supplied, water level in the tank 36 rises and water pressure is applied to the bottom plate 38 of the tank 36. Consequently, the bottom plate 38 is deflected and the capacity of the tank 36 increases correspondingly.