A semiconductor device structure is provided which includes a first field effect transistor having a first channel region, a first source region, a first drain region and a first gate conductor overlying the first channel region. Each of the bipolar plates has a nested active area and a non-nested feed area which also may serve as active area. The concentration of the circulating anolyte is detected, and based on this detected value the supplying amount of the base NaOH solution is controlled and electrolysis is performed.