Provided is a microbubble generating device with a simple structure that can stably and continuously discharge microbubbles in larger volumes from a discharge section. The microbubble generating device is provided with: a liquid introduction section 2 for introducing a liquid L1 within a tank T; a gas introduction section 3a for introducing a gas; a pressure feed section 4 for pressure feeding a liquid fluid L2 fed via the liquid introduction section 2 and the gas fed via the gas introduction section 3a; a microbubble generating section 5 for generating microbubbles B in the liquid fluid L2 pressure fed by the pressure feed section 4 and discharging the liquid fluid to the liquid L1; and a discharge flow rate adjustment section 55 for adjusting the discharge volume of the liquid fluid L2.