A waster water treatment apparatus has micro-nano bubbles generation tanks, mixing tanks, a submerged membrane tank, a contact oxidation tank, and an activated charcoal adsorption device. In the micro-nano bubbles generation tanks, micro-nano bubbles are added to the waste water. In the mixing tanks, the waste water containing micro-nano bubbles is mixed with sludge containing microorganisms. In the contact oxidation tank, the waste water containing organofluoric compounds is microbially treated by the micro-nano bubbles added to the waste water. The micro-nano bubbles activate microorganisms in the waste water. Thereby organofluoric compounds are microbially decomposed with effect.