The present invention relates to a method for configuring a master/slave board during initial booting of a redundant board, and a board thereof. A master/slave configuration method for a redundant board, according to an embodiment of the present invention, comprises: initializing redundant first and second boards, respectively, when a boot voltage is applied thereto; allowing the first and second boards to generate initialization completion information, respectively, according to the completion of the initialization so as to transmit same to a lower-rank board, respectively; allowing the lower-rank board to compare reception time points of the initialization completion information respectively received from the first and second boards so as to generate master/slave configuration information; allowing the lower-rank board to transmit the generated master/slave configuration information to the first and second boards, respectively; and allowing the first and second boards to configure same as either a master board or a slave board according to the respectively received master/slave configuration information.