We present results of investigations devoted to searching of ways for sol-gel derived SnO2 thin-film hydrogen sensors performance improvement. To that end we studied the as-prepared sensors parameters changes in real time during short- and long-term operation in gas-air mixture and known operating temperature conditions. It was established that in comparison with as-prepared sensor parameters such initial operation mode leads to the rise of the sensors sensitivity on more than two orders of magnitude, improvement of the sensor parameters stability in time. Obtained experimental data are in a good accordance with known theoretical results. (C) 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.