Abstract: The first preferred embodiment of the subject invention is a mounted stairway built on a central single stringer which utilizes stairs horizontally adjustable with regard to inclination of the stringer. The stairs are fixed in the middle by means of splined bolts which fit into splined apertures both of the stringer and tread angles. The railing posts are screwed into bushings of the tread and secured. Brackets screwed on railing post heads have swivels holding the rails in position.The second embodiment is another option of the mounted stairway which utilizes two side stringers for wider stairs. The stairs in this case are fixed from aside by means of two splined bolts to match splined apertures of both stringers and tread angles.