A display method can be flexibly applied to suppress the power consumption and a device and display method which can reduce the power consumption while the image quality is prevented from being deteriorated are provided. A display device which can be operated in a progressive mode and interlace mode includes a display portion having a plurality of pixels arranged thereon and a gradation correction table which stores data used to correct a difference between a gradation level when the display portion is driven in the progressive mode and a gradation level when it is driven in the interlace mode. Then, when video data supplied to the display portion is set in the interlace mode, a timing controller corrects the video data by use of data in the gradation correction table.