This invention provides a fine bubble generating apparatus which can efficiently generate fine bubbles on the nanometer level. This apparatus comprises a cylindrical member (40) having a cylindrical inner peripheral surface, a first end wall member (42) configured to close one end of the cylindrical member, and a second end wall member (44) configured to close the other end of the cylindrical member. The cylindrical member (40) and the first and second end wall members (42) and (44) define a fluid swirling chamber (46). The cylindrical member has a fluid inlet hole (48) at a position close to the second end wall member (44) to supply a gas-liquid mixed fluid in the tangential direction of the peripheral surface of the fluid swirling chamber (46). The second end wall member has a fluid outlet hole (50) extending therethrough along the center axis of the inner peripheral surface of the fluid swirling chamber. The gas-liquid mixed fluid is introduced into the fluid swirling chamber at a position close to the second end wall member. Most of the fluid is directed toward the first end wall member while swirling along the inner peripheral surface of the fluid swirling chamber, reversed from the first end wall member toward the second end wall member and discharged through the fluid outlet hole.
