To replace a mounting board easily by a method wherein the mounting board, connection parts connected to the mounting board, and a clip or a connector which connects the mounting board and the connection parts together are provided.

A pressure rubber 18 is provided to the rear of a connection pattern of a flexible board 15. The connection pattern of the flexible board 15 is made to confront the connection pattern of a mounting board 1, and the pressure rubber 18 is interposed between the mounting board 1 and a pressure mold 16 and fixed by a pressure clip 17. The force of the pressure clip 17 is applied as a plane pressure to the pressure mold 16 to fix the board 1. The pressure clip 17 is unfastened, and the pressure mold 16 and the pressure rubber 18 are removed, whereby board 1 can be easily replaced.