In a previous paper (KUBOTA et al., 1990, Lu et al., 1990), we have studied a convenient microwave heated drying instrument, and studied the simple drying-rate equations of potato and so on by using the some shapes of samples. And then, we observed that the browning according the temperature rises increased by increasing in size of potato samples, and the browning depended on the location. In this paper, we studied the relations among the size and shape and the browning on microwave heated drying of potato, and we could decrease the browning according the temperature rises by gradually reducing the maximum length and the thickness.