A raw material solution (6), in which an organic semiconductor material is dissolved in a solvent, is supplied to a substrate (1). The solvent is evaporated so that crystals of the organic semiconductor material are precipitated. Thus, an organic semiconductor thin film (7) is formed on the substrate (1). An edge forming member (2) having a contact face (2a) on one side is used and located opposite the substrate (1) so that the plane of the contact face (2a) intersects the surface of the substrate (1) at a predetermined angle. The raw material solution (6) is supplied to the substrate (1) and formed into a droplet (6a) that comes into contact with the contact face (2a). The substrate (1) and the edge forming member (2) are moved relative to each other in a direction parallel to the surface of the substrate (1) so as to separate the edge forming member (2) from the droplet (6a), and while the raw material solution (6) is supplied so that a change in size of the droplet (6a) with the relative movement is maintained within a predetermined range, the solvent contained in the droplet (6a) is evaporated to form the organic semiconductor thin film (7) on the substrate (1) after the contact face (2a) has been moved. In this manner, a large-area organic semiconductor single crystal thin film having high charge mobility can be manufactured by a simple process using a solvent evaporation method based on droplet formation.