An atomizing diffuser for gaseous environment cleaning: includes a tank cover covered in a water tank to define an oscillation space in the tank cover so as to enhance the effect of oscillating atomized liquid, a housing shield shielding the tank cover and provided with a water filling hole for allowing direct filling of liquid in the water tank and the oscillation space, and an oscillation device with the oscillator thereof coated with a layer of acid and alkali resistant coating for oscillating the alkaline ionized water and other acid-alkaline cleaning liquids in the oscillation space into gaseous cleaning mist that is outputted to the external environmental space for sterilization, cleaning, deodorization, virus elimination, or air purification, and an umbrella-shaped panel with radial ribs provided in the housing is illuminated by light to show the beauty of a paper umbrella, matching the spray effect.