A disposable gas diffusion device includes a gas supply device, which includes therein a gas inlet device, which includes a coupling section, and a compression element. The coupling section includes therein a gas conveyance hole. A container has an end connected to a diffuser that is provided with a gas entrance passage having an opposite end extending to a bottom of the diffuser. The bottom of the diffuser is provided with a liquid guiding device, which has an opposite end extending to a location adjacent to a bottom of the container. The diffuser has a top end in which an exit opening is formed. The gas supply device is operable to guide a pressurized gas into the container on induce a negative pressure zone inside the container in order to convey a liquid through the liquid guiding device to an atomization hole to be atomized and sprayed out.
