Disclosed is a device for discriminating the right sides of test strips in an automated analyzer for arranging the test strips such that the right sides thereof may face in one direction, which comprises: suction holes formed on a transportation stage to be aligned in the direction orthogonal to the direction that the test strips are moved, at the positions corresponding to the intervals between test pads impregnated with reagents of the test strip; and suction holes formed on a turntable disposed subsequent to the transportation stage, at the positions corresponding to the intervals between the test pads impregnated with reagents of the test strip.