PURPOSE: To relax the restriction in height of the mounting parts by a method wherein a sheet of substrate is cut, and a stepped substrate is formed by soldering a through hole and a land.

CONSTITUTION: This stepped substrate is composed of a main substrate 16 and a secondary substrate 18. The main substrate 16 and the secondary substrate 18 are integrally formed in the state wherein they are electrically connected by soldering electrode 20, which are obtained by cutting through holes, and lands 20. Through holes 26, with a conductive layer formed in the inside, are formed in a row on the substrate 24, and the lands 22 are formed on one side of the substrate 24 in a one-to-one corresponding manner with the through holes 26. Then, the substrate 24 is cut along the arrangement line of the through holes. The cut main substrate 16 and the secondary substrates 18 are laminated in such a manner that the electrode 20 and the lands 22 are brought into contact with each other. By soldering the lands 22 and the electrodes 20 in the above- mentioned state, the main substrate 16 and the secondary substrate 18 can be integrated, and a stepped substrate can be obtained.