Stairway

A staircase comprising:

• a pair of right and left truss structural members which are inclined with the slope of the staircase and
• a plurality of treads disposed between the truss structural members, wherein
• each truss structural member is composed of an upper chord member having a plurality of column-shaped upper node members provided in series in the direction of the staircase inclination, a lower chord member having a plurality of column-shaped lower node members provided in series in the direction of the staircase inclination, and lattice members that link the upper chord member and the lower chord member to each other,
• each upper node member and each lower node member are disposed so that the axes thereof are orthogonal to the truss plane of the truss structural member, and on the outer circumferential faces thereof, a plurality of linking grooves are formed along the axes, and
• the lattice member has flat-shaped linking end parts that can fit into the linking grooves on both ends, one of the linking end parts is fitted into the linking groove of the upper node member, the other one of the linking end parts is fitted into the linking groove of the lower node member, and
• the ends of each tread are fixed to the side end face of the upper node member and the side end face of the lower node member.