The present study investigates on improvement of inhalation efficiency of hood in ventilation system for elimination of industrial dust. The hood, one of local exhaust ventilation system, has an important function to inhale a pollution source such as harmful dust and industrial waste. In this study, in order to improve the inhalation efficiency of the industrial hood, a new device named "gas-guide-device" was attached to inside of hood. The thermal fluid commercial code "Phoenics ver 3.1" was used to analyze the flow velocity distribution at the hood inlet and around the hood after gas-guide-device was installed. And the flow velocity on each position inside and around the hood was actually measured using the hot wire type anemometer under the same condition as that of numerical analysis. Also, in order to identify the optimum shape of gas-guide-device, numerical analysis and experiments are performed under various conditions and their results are presented. The results of this study revealed that the hood attached with gas-guide-device was higher the inhalation efficiency than that for without one and can be possible to improve the capture velocity of the industrial dust. And the optimum shape of gas-guide-device was identified that the ratio of two sizes of gas-guide-device, X to Y, has 4 to 6 on the basis of the hood size in use and the width (b) of gas-guide-device.