The present invention provides a liquid atomizer for atomizing liquid and applied in an atomizing device having an accommodating space and a through hole. The liquid atomizer includes a vibrating element having a first hole corresponding to the through hole; a spray plate having a plurality of spraying holes corresponding to the first hole and being connected with the vibrating element; and a structure element having a second hole corresponding to the plurality of spraying holes of the spray plate and being connected with the spray plate so that the spray plate is disposed between the vibrating element and the structure element. The vibrating element, the spray plate and the structure element are assembled in the accommodating space of the atomizing device. Liquids are atomized via the spraying holes of the spray plate.