To provide a thinned display device with a touch sensor and to provide a highly reliable display device. A sensor layer including an electrode of a touch sensor is formed in advance over a support substrate which is different from a substrate which forms a display device so that the sensor layer can be separated, the sensor layer is separated from the support substrate, and the separated sensor layer is attached to one surface of a substrate the other surface of which is provided with a component such as a color filter, with a bonding layer interposed therebetween.