This invention relates to a device and a method for forming elongated material. A device (824-864) according to the present invention for forming elongated material, is characterised in that the device comprises a track (821) for guiding the material in the device, wherein the track is arranged to guide the movement of the material into a desired form when the material is fed into the device, and the device comprises an opening (823, 824) along the entire length of the track for removing the elongated material from the device after the formation. With this invention it is possible to make knots and other structures of desired geometry easily and efficiently.