To provide a device and a method for supplying emulsified fuel enabling not only combustion with reduced Nox, SOx and dust but also stable combustion and for suppressing separation of the emulsified fuel.

The device and method for supplying emulsified fuel include: a stirring tank 10 for stirring fuel, water and additive; a filter 33 for filtering stirring liquid; an emulsified fuel tank 34 for storing the emulsified fuel; an upstream bypass pipe 13 for supplying the fuel to the stirring tank 10; and a downstream bypass pipe 36 for discharging the emulsified fuel stored in the emulsified fuel tank. On the fuel tank side from a supply shut-off valve, the upstream bypass pipe is connected to a fuel supply pipe, and on a combustion device side from the supply shut-off valve, the downstream bypass pipe is connected to the fuel supply pipe. A volume ratio between the fuel and water is 65-90%: 35-10%, and a volume ratio of the additive to the emulsified fuel is 0.25-0.45%.