To prevent the impairment of appearance caused by the exposure of screws without complicating structure, in a chair whose backrest is fixed to front faces of back support columns with the screws.

A back frame 7 has the left and right back support columns 29, and an upper back shell plate 10 is fixed to the back support columns 29 with the screws 31 which penetrate upper ends of the back support columns 29 from the rear. Elbow bodies 38 each having a lateral facing part 36 and an elbow support 37 are integrally formed at upper parts of the back support columns 29, and elbow covers 39 are attached to the elbow bodies 38. The elbow covers 39 have rear walls 77, and heads of the screws 31 for fixing the upper back shell plate 10 are covered with the rear walls 77. Thereby, the heads of the screws 31 are not exposed and the appearance is not impaired.