The present invention relates to a washing machine (1) wherein an ozone generator (4) that generates ozone gas is used for increasing the washing performance and providing sanitation. The ozone gas generated by the ozone generator (4) is delivered directly onto the clothes inside the tub (2) without mixing with the wash water and hence without dissolving in the wash water, and furthermore the ozone generator (4) that gets overheated due to operation at high voltage is cooled by the water used in the washing process.