An atomizer used in the inner combustion engine and having energy saving and debris reducing function, which includes: a housing having an inlet pipe and an outlet pipe, the interior of the housing is installed with a flow regulating mask, and a bottom plate is installed inside the housing； a working fluid filled in the housing and disposed above the bottom plate； a floating carrier installed in the housing and floating on the liquid surface of the working fluid； at least an atomizing mechanism installed on the floating carrier； and a sensing controlling mechanism installed below the bottom plate and connected to the atomizing mechanism. Accordingly, with the driving and regulating provided by the sensing controlling mechanism, the flow regulating mask allows the atomizing mechanism to atomize proper amount of water with respect to the actual conditions of the rotation speed and loading status of an engine.
