PURPOSE: To assure the fixation of a printed wiring board and a guide for the board upon its removal by providing a fitting part on a substrate supporting member, which is disposed on a substrate mounted adjoining to the present substrate, the fitting part snugly fits to the substrate supporting member and assists the removal and insertion of the present substrate.

CONSTITUTION: A fitting part 3 is formed on a substrate supporting member 1 which is disposed on one end of a substrate 13 for fixedly mounting the present substrate 13 on a casing. The fitting part 3 is snugly fitted to a substrate supporting member 1 disposed on a substrate 13 mounted on the present substrate 13 adjoining to the same and assists the removal and insertion of the preset substrate 13. For example, a substrate supporting metal plate such as iron or aluminum. The male fitting part 3 is protruded by forming a stepped portion slightly deeper than the thickness of the plate member on one end of the plate member by making use of a press, and a female fitting part, which snugly fits into the fitting part 3 of the adjacent substrate supporting metal 1 is formed on the other side of the same. Furthermore, a mounting hole 9 and a screw hole 9a are drilled through a body part of the substrate supporting metal fitting 1 for mounting the substrate supporting metal fitting 1 on the printed wiring substrate 13 via a connector 9c.