A vaporizing device such as an electronic cigarette includes a housing (11) containing a battery (12) or other electrical power source electrically connected to a high frequency oscillation circuit (50). Two electrodes or electrode pads (56) with a liquid space (70) between them are electrically connected to the high frequency oscillation circuit (50).A liquid supply (34) in the housing (11) provides a liquid into the liquid space (70). The high frequency oscillation circuit (50) is switched on by a manual switch or by a sensor (24) sensing inhalation by a user. The liquid is vaporized by dielectric heating.