To provide a chair to solve a problem of a conventional stomachache/backache prevention health chair that it acts acupressure beat on the abdominal region by resilient repulsion using springs at the sites, and arms are pressed against an armrest part, a forward bending posture and crossing legs on the seating region take off the freedom of hands and legs and are unstable to lack security and safety.

In the secure reverse-sitting chair, springs are removed from the sites, the shape of an abdominal rest part A is exchanged at one touch by a slide rail according to the situations, to act on positions matched with a body shape. Independent foot rest parts C, D, E are changed by diversified foot changes at positions matched with the length of a foot. Thus the chair has an adjustment mechanism to enable a user to take a standing sitting posture.