To facilitate the energization of plating process of a substrate for housing a high frequency and high heat radiation type semiconductor element having a base metal for heat radiation and a lead metal which are electrically insulated from each other.

A lead metal 1a joined to a surface of a ceramic frame body 4a is electrically connected with a base metal 6a joined to a rear surface of the ceramic frame body 4a with a through hole 7a formed in the ceramic frame body 4a and a plating conduction pattern 8a. Electric power is supplied from a lead frame part 3a connecting with the lead metal 1a to perform plating process on surfaces of the lead metal 1a and the base metal 6a. After the plating process, the plating conduction pattern 8a and an area between the lead metal 1a and the lead frame part 3a are cut.