Objects are to reduce damage to a semiconductor integrated circuit by external stress and to increase the manufacturing yield of a thinned semiconductor integrated circuit. A single crystal semiconductor layer separated from a single crystal semiconductor substrate is used for a semiconductor element included in the semiconductor integrated circuit. Moreover, a substrate which is formed into a thin shape and provided with the semiconductor integrated circuit is covered with a resin layer. In a separation step, a groove for separating a semiconductor element layer is formed in the supporting substrate, and a resin layer is provided over the supporting substrate in which the groove is formed. After that, the resin layer and the supporting substrate are cut in the groove so as to be divided into a plurality of semiconductor integrated circuits.