Abstract: A microbubble generating device that is capable of generating microbubbles from contaminated water is provided. The microbubble generating device 10 according to the present invention includes a liquid flow path 11 through which a pressurized liquid flows, a discharge path 12 through which generated microbubbles and a liquid are discharged, a throat part 13 that connects the liquid flow path 11 and the discharge path 12, and that has a flow path area smaller than the area of the liquid flow path 11 or the discharge path 12, and a gas supply path 14 for supplying a gas into the liquid flow path 11 or the throat part 13, wherein the gas supply path 14 has an exit end 143 that opens toward the downstream side of the liquid flow.