A wafer processing apparatus includes a controller connected to a first robot and a second robot. The controller controls the first robot so that the wafer is placed on a first load lock stage in such a way that the center of the wafer is shifted from the center of the first load lock stage by a first position shift amount and another wafer is placed on a second load lock stage in such a way that the center of the wafer is shifted from the center of the second load lock stage by a second position shift amount. The controller controls the second robot so that the second robot simultaneously conveys two wafers between the first and second load lock stages, and a first processing stage and a second processing stage.