The present invention is a portable electronic vapour-producing device which converts chemical substances in liquid form to a gaseous form so that active ingredient( s) can be inhaled by the user for therapeutic or medicinal purposes. The device includes: a power module: a primary module: and an auxiliary module that may be enclosed separately in exterior hollow casings and fitted together, or enclosed together in one single exterior hollow casing. The primary module includes: an anode assembly: a cask assembly: and a heater assembly. The anode assembly includes an anode barrel, which is hollow, fixed permanently in place and contacts the batten : a cathode mount, which is fixed permanently in place and contacts the heater assembly: and an anode mount, which moves between contacting the anode and not contacting the cathode in response to a vacuum produced by user inhalation.