Abstract: A series of highly economical metal channels each having a first and second side members extending vertically downward from a third horizontal member for accommodating thereto a step and a riser for rapidly, yet sturdily forming a stairway is disclosed. A plurality of quickly-installed attaching means for integrally coupling together a combination of a generally rectangular beam, metal channel, step and riser are used at various areas of said stairway in order to avoid thereto the time-consuming and expensive manner of providing a sawtooth-type stairway beam.