Seat element, comprising a frame, a seat associable to said frame, the frame and the seat being made separately from each other and being attachable and detachable from each other by the interposition of first coupling means. Advantageously, the first coupling means comprise at least one elastic hook and a protuberance, able to form a snap coupling with each other, the elastic hook being positioned so as to intercept the protuberance in a vertical assembly direction.The elastic hook has a coupling end and a hook end, flexible in relation to the coupling end, so as to snap hook onto an undercut of the protuberance in the vertical assembly direction.