A capacitive gas sensor and a method of fabricating the same are provided. The capacitive gas sensor includes an insulating substrate, a metal electrode and a micro thin-film heater wire integrally formed on the same plane of the insulating substrate, and an oxide detection layer coated on the metal electrode and the micro thin-film heater wire. The fabrication method includes depositing a metal layer on an insulating substrate, etching the metal layer so that a metal electrode and a micro thin-film heater wire form an interdigital transducer on the same plane, and forming a nano crystal complex oxide thin film or a complex oxide nano fiber coating layer on the metal electrode and the micro thin-film heater wire as a detecting layer. The capacitive gas sensor can be easily fabricated and can have excellent characteristics such as high sensitivity, high selectivity, high stability, and low power consumption.