An atomizing device includes an atomizing sleeve, an air
pipe received in the atomizing sleeve, an annular space being formed between the air
pipe and the atomizing sleeve for containing a tobacco oil, an oil obstructing ring located at an end of the air
pipe, the oil obstructing ring having an oil hole, an atomizing
assembly positioned under the oil obstructing ring, a screw sleeve and an
electrode respectively electrically connected to the atomizing
assembly; and a flexible membrane having an inner wall attached to the
electrode, and an outer wall in contact with an inner wall of the screw sleeve. The flexible membrane is capable of deformable to form an
air space between the outer wall of the flexible membrane and the inner wall of the screw sleeve. An
electronic cigarette using the atomizing device is also provided.