To provide a blending device capable of securing a flow velocity sufficient for hot water to flow through the whole inside of a blender even when the supply amount of the hot water is small, and a beverage dispenser using it.

The blending device has a blender 10 for blending powder supplied from a raw material box 2 and hot water supplied from a hot water supplier 3 and an agitator 11 for agitating and discharging liquid mixed in the blender 10. Between the hot water supplier 3 and the blender 10, an on-off valve 5 capable of sending out hot water supplied from the hot water supplier 3 to the blender 10 or not sending it out by opening/closing operations is provided. The on-off valve 5 is connected to a control part 6 for controlling the opening/closing operations, and the control part 6 makes hot water from the hot water supplier 3 be intermittently sent out to the blender 10 by turning the on-off valve 5 to an open state according to a prescribed time pattern.