A substrate manufacturing method is disclosed. A substrate manufacturing method, comprising: providing a support body on which a first separation layer is formed; forming a second separation layer on the first separation layer; forming an adhesion layer which covers the first separation layer and the second separation layer; forming a circuit stack body on the adhesion layer; cutting the circuit stack body, the adhesion layer and the second separation layer to a pre-determined shape; and forming a circuit stack unit by separating the second layer from the first layer, provides easy separation of the circuit stack pattern, which formed on the support body, from the support body and reduced manufacturing cost by reducing number of process and required materials for manufacturing coreless thin substrate.