An object of the present invention is to provide a method for manufacturing a semiconductor device of which manufacturing process is simplified by improving usage rate of a material. A method for manufacturing a semiconductor device of the invention comprises the steps of: forming gate electrodes with a droplet discharge method on a substrate having an insulating surface; laminating gate insulating layers, semiconductor layers, and a semiconductor layer containing one-conductivity type impurity over the gate electrodes; forming first conductive layers serving as masks with a droplet discharge method in a position overlapping the gate electrodes, etching the semiconductor layer and the semiconductor layer containing one-conductivity type impurity with the first conductive layers, forming a second conductive layer serving as a source wiring or a drain wiring with a droplet discharge method over the first conductive layers; and etching the first conductive layers and the semiconductor layer containing one-conductivity type impurity, using the second conductive layers as masks.