PURPOSE: To eliminate the need for excess parts, to reduce force for insertion and to regulate a position by installing a spacer for regulating the position of fitting near the connector of a moving body, releasing the regulation of a guide opposed to the spacer when the connector starts its fitting and controlling the guide until the connector starts its fitting.

CONSTITUTION: A card 3 in the left and right direction is regulated by a holder 1 and no swinging is generated. Since swinging in the vertical direction is often generated, however, vertical positions are controlled by a spacer 4 and a guide 2 before a connector 5 is fitted. When fitting is started, excess force for insertion is unnecessitated because the spacer 4 crosses over the guide 2. The holder 1 fills the role of regulation in the left and right direction of the card 3. When projections are formed on the outside of the card 3 side only to a first section, where the card 3 is slid, and a section slightly before the card is fitted to the connector 5 and a guide 2 for regulating positions is formed on the inside of the holder 1 side, force at the time of the insertion of the connector 5 is further reduced.