BOARD EXCHANGE SYSTEM

PURPOSE:To enable an insertion/extraction means of a self-running board insertion/extraction robot to be positioned accurately at an insertion/extraction position of a printed board specified by a host device even in the case where a fixing position of a board mounting unit with respect to the chassis of an electronic device is displaced from a regular position. CONSTITUTION:After being moved to the center position of an origin mark, a first mark sensor 11 is moved to the expected center position of one reference mark of a target stage of a target board mounting unit to make an operator 31 operate the actual center position of this reference mark, so that the first mark sensor 11 is moved to the expected center position of the other reference mark of the stage. The actual center position of this reference mark is operated by the operator 31, and the center position of a target printed board is operated from the actual center position of both reference marks, so that the insertion/ extraction means is moved to the operated center position.