The invention relates to an item of transformable furniture, more particularly to an item of furniture transformable from a chair into a desk and vice versa, from a desk into a chair. The item of transformable furniture comprises a first plate (5) and a second plate (6), linked to each other by a hinge joint (4), where said two plates can rotate respectively round first and second horizontal (2, 3) axes so that the plates can be moved from a first position as seat and back, respectively, to a second position as front panel (17) and worktop (18), respectively, and vice versa. Said plates are linked by said first and second horizontal axes to a supporting construction, which consists of at least three interconnected folding elements (1, 1′, 19).