An atomizer and an electronic cigarette having same include an atomizing sleeve with a liquid storage chamber formed therein; a mouthpiece is disposed at a top end of the atomizing sleeve; an air passage pipe is disposed at a center of the atomizing sleeve; a supporter with two ends opened is disposed at a bottom end of the air passage pipe; a hollow heating element is disposed in the supporter longitudinally; a side wall of the supporter has at least one liquid inlet hole communicated with the liquid storage chamber and configured for allowing radial infiltration of the tobacco liquid to the heating element; a sealing component is disposed between the heating element and the supporter to encircle the heating element and configured for avoiding leakage of the tobacco liquid along a longitudinal direction of the heating element.