According to one embodiment, a vaporizing system comprises first and second tanks that can accumulate liquid source and first, second, and third pipes. The first pipe allows first gas to be sent out of the first tank. The second pipe allows second gas to be sent out of the second tank. The third pipe is connected to the first and second pipes and allows the first and second gas to be sent out to an external apparatus. The first tank is placed on an upper side of the second tank in a stacked manner.