In order to connect a PCI standard insertion board (which will hereinafter be referred to as PCI board) to the control board, a dedicated adapter for the PCI board is needed. Similarly, in order to connect a PCIe standard insertion board (which will hereinafter be referred to as PCIe board) to the control board, a dedicated adapter for the PCIe board must be prepared. In other words, each of the PCI board and the PCIe board can be attached only to the adapter that corresponds to its own standard.

It is therefore an object of the present invention to provide an adapter that facilitates selective attaching of a PCI board and a PCIe board thereto.

According to the present invention, an adapter configured to be inserted into a slot of an electronic device and also configured to connect each of a PCI (Peripheral Component Interconnect) board and a PCIe (Peripheral Component Interconnect-express) board to a control board that is installed on a side of the slot toward which the adapter is inserted, includes a base plate. The base plate includes: a holding structure configured to selectively hold a PCI relay board configured to connect the PCI board to the control board and a PCIe relay board configured to connect the PCIe board to the control board; and an attachment structure configured to selectively attach a PCI bracket configured to fix the PCI board to the base plate and a PCIe bracket configured to fix the PCIe board to the base plate.

The present invention can provide an adapter by which it is easy to selectively attach a PCI board and a PCIe board to the adapter.