The present invention relates to an apparatus for sensing and controlling a gas supply amount, and a method for sensing and controlling a gas supply amount thereby, the apparatus being configured so as to be capable of continuously maintaining the originally preset supply amount while allowing the gas supply amount to be sensed in real time by a light sensor on the basis of the number of bubbles generated at an arbitrarily set time difference when target gas flows in a tube, thereby being capable of identifying more accurately the supply amount or faulty supply state, wherein a series of automated devices control the pressure of the tube in real time so as to precisely realize a target supply amount according to gas supply information obtained from the light sensor, thereby actively preventing malfunction. The apparatus comprises: a tube (1) which allows target gas to flow from the bottom to the top a sensing unit (10), engaged with the external surface of the tube, for sensing the number of bubbles of the target gas, which sequentially moves for a predetermined period of time in the inner space of the tube, in real time, through application of the light sensor on the basis of signal information of a light emitting diode and a transistor positioned to correspond to each other a control unit for receiving bubble information from the sensing unit and determining whether the bubble information matches the target gas supply amount in comparison to a preset time and a pressure adjustment unit (20), operated by signals obtained from the control unit, for determining whether to block the inner space of the tube in a manner that the pressure adjustment unit (20) rotates at an angle proportional to the number of pulses provided through a motor, thereby varying the number of bubbles during a certain period of time to match the target gas supply amount.La présente invention concerne un appareil permettant de détecter et de réguler une quantité dalimentation en gaz, et un procé
