To provide a bridging type ultrasonic atomizing apparatus which has a function of preventing a no-liquid driving, and is easily standardized in the manufacturing process.

When an input electric signal is impressed on an input piezoelectric board 1, a 1st elastic oscillation is excited. The first elastic oscillation is transmitted to a porous nonmetallic plate 7. In this case, when liquid is present on the plate 7, the liquid is atomized. The 1st elastic oscillation causes a 2nd elastic oscillation in an output piezoelectric board 4. The 2nd elastic oscillation is detected as a delayed electric signal, and impressed again as an input electric signal on the input piezoelectric board 1. When the liquid is absent on the porous nonmetallic plate 7, the 2nd elastic oscillation does not occur in the output piezoelectric board 4. Consequently, a no-liquid driving, that is, a driving in the state in which liquid is not supplied on the porous nonmetallic plate 7, is prevented.

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