A nebulizing device includes a medicament storage module, a nebulizing unit, and a first waterproof gasket. In the medicament storage module, a coupling part is connected with an outer surface of a tubular sidewall and aligned with an outlet of the tubular sidewall, and includes an extension wall and a first recess where the nebulizing unit is disposed. The first waterproof gasket is disposed within the first recess and located on a side of the nebulizing unit farther from the outlet. In the first waterproof gasket, a first opening is disposed adjacent to the nebulizing unit, a second opening is disposed opposite to the first opening and located on a side of the first opening farther from the nebulizing unit, the size of the second opening is greater than that of the first opening, and the annular wall structure is connected to the first opening and the second opening.