An electronic cigarette particularly adaptable to vaporize liquid material also having exhale filter function is disclosed herein. The exhale function is useful to prevent second hand smoke in an enclosed environment, for example. An innovative diverter valve assembly comprises a unique duckbill valve configuration diverting air through a cooker chamber and into a mouthpiece in an inhale function and diverting exhaled air around the cooker chamber in the exhale function and through a filter assembly. A preferred embodiment further introduces a unique shape to the smoking instrument being elliptical in the cross-section and tapering to proximal and distal ends.