The present invention relates to a functional chair having functions for assisting standing and sitting, and the purpose is to provide a functional chair having functions for assisting standing and sitting, which improves motions of a seat plate part to stably support standing and sitting of user. To this end, the present invention comprises: a seat plate part； a leg part which contains a flat support shaft for supporting the seat plate part； and a connection part which connects the support shaft to the seat plate part, uses a three-bar link structure and an elastic force of an elastic member to induce rotating and sliding motions of the seat plate part, switches a posture of the seat plate part to a first posture which is flat, and a second posture which is inclined forwardly, and operates the seat plate part to assist standing and sitting of a user. The connection part comprises: a fixing bracket which protrudes toward a rear side from the support shaft； a first rotational bracket of which one side end is coupled to a rear end of the fixing bracket to be able to rotate； a second rotational bracket of which a rear end portion is coupled to the other side end of the first rotational bracket to be able to rotate, and an end portion has a slot, into which a fixed bar protruding toward a front of the support shaft is inserted, formed thereon, and which is coupled to a bottom surface of the seat plate part； and an elastic member which accumulates energy in a process where the seat plate part in the second posture is switched to the first posture, and uses the accumulated energy to induce the seat plate part in the first posture to be switched to the second posture. The slot has a bottom end to be opened in order to enable the fixed bar to be inserted and separated.본 발명은 기립 및 착석 보조기능을 갖는 기능성 의자에 관한 것으로, 그 목적은 사용자의 기립 및 착석을 보다 안정적으로 지지할 수 있도록 좌판부의 움직임이 개선된 기립 및 착석 보조기능을 갖는 기능성 의자를 제공함에 있다. 이를 위한 본 발명은 좌판부； 상기 좌판부를 지지하는 수평한 지지축을 포함하는 것으로 이루어진 다리부； 및 상기 지지축과 좌판부를 연결하도록 이루어지
