A method for manufacturing an interposer including forming a capacitor over a semiconductor substrate; forming a first resin layer with a first partial electrode buried in over the semiconductor substrate and the capacitor; cutting an upper part of the first partial electrode and the first resin layer with a cutting tool; forming a second resin layer with a second partial electrode buried in over a glass substrate with a through-electrode buried in; cutting an upper part of the second partial electrode and the second resin layer with the cutting tool; making thermal processing with the first resin layer and the second resin layer adhered to each other while connecting the first partial electrode and the second partial electrode to each other; removing the semiconductor substrate; forming a third resin layer over the glass substrate, covering the capacitor; and burying a third partial electrode in the third resin layer.