The invention relates to an apparatus for rolling a strip (21) comprising a first work roll (24), which is mounted from both ends with bearings (35) to the mill frame, a second work roll (25), which work rolls (24, 25) are forming a nip (26) in between them, one or more ring(s) (19, 20) closing inside at least one of the work rolls (24, 25), at least first intermediate roll (27, 39) mounted to the mill frame from both ends with bearings (36) and arranged in rolling contact between the second work roll (25) and inside surface (22) of the ring(s) (19, 20) The invention also relates to the method of producing a thin strip.