Abstract: An ergonomic self-balancing armchair having a seating element, a holding support and a mechanism for regulating the angular position of the seating element. The regulating mechanism has an articulated triangle structure, in which the angular ends define free turning spindles. One side of said triangle defines a fixed length and fixed position, and a second side defines fixed length and tilting position, and a third side defines variable length and tilting position. The seating element is supported and fixed upon the second and third sides, whereas through the first side is assembled the supporting mechanism. The spindle is made up of the torsion bar that is mounted so that it turns freely upon side and has fitted at one end side and the opposite end a regulating control lever.