Apparatus for producing an underfloor fibreboard turn element for underfloor heating having a plurality of turn notches or grooves for floor heating loops, the apparatus comprising - a first reservoir for fibreboards to be processed in the apparatus, - a cutter device comprising a main frame supporting a cutter means including an elongated cutter frame holding a plurality of rotatable axially cutting cutter wheels with axes of rotation oriented in parallel, each of said cutter wheels having a plurality cutters arranged on a circumference thereof with first cutting edges oriented axially away from the wheel and so as to cut in a common plane oriented perpendicular to said axes of rotation, a plane base for supporting and positioning a fibreboard with a first surface thereof in a surface plane being in parallel with the common plane of the cutters and having an opening for the cutter wheels, and a drive means for rotating the cutter wheels, and the cutter device further comprising a moving means for moving the cutter means in a direction towards and away from the plane base for the cutters of the cutter wheels to pass through the opening in the plane base and past the surface plane, - a feeding device for feeding the fibreboard from the reservoir to the plane base of the cutter device, characterised in that it comprises: - a positioning device for positioning and securing the fibreboard on the plane base in a predetermined position with the first surface against the plane base and such that the cutter wheels on passing through the opening cut respective circular grooves or notches in predetermined parts of the first surface of the fibreboard, - a storage device for storage of fibreboards processed in the cutter device, and - a transporting device for transporting the processed fibreboard from the plane base to the storage device. - a first reservoir for fibreboards to be processed in the apparatus, - a cutter device comprising a main frame supporting a cutter means including an elongated cutter frame holding a plurality of rotatable axially cutting cutter wheels with axes of rotation oriented in parallel, each of said cutter wheels having a plurality cutters arranged on a circumference thereof with first cutting edges oriented axially away from the wheel and so as to cut in a common plane oriented perpendicular to said axes of rotation, a plane base for supporting and positioning a fibreboard with a first surface thereof in a surface plane being in parallel with the common plane of the cutters and having an opening for the cutter wheels, and a drive means for rotating the cutter wheels, and the cutter device further comprising a moving means for moving the cutter means in a direction towards and away from the plane base for the cutters of the cutter wheels to pass through the opening in the plane base and past the surface plane, - a feeding device for feeding the fibreboard from the reservoir to the plane base of the cutter device, characterised in that it comprises: - a positioning device for positioning and securing the fibreboard on the plane base in a predetermined position with the first surface against the plane base and such that the cutter wheels on passing through the opening cut respective circular grooves or notches in predetermined parts of the first surface of the fibreboard, - a positioning device for positioning and securing the fibreboard on the plane base in a predetermined position with the first surface against the plane base and such that the cutter wheels on passing through the opening cut respective circular grooves or notches in predetermined parts of the first surface of the fibreboard, - a storage device for storage of fibreboards processed in the cutter device, and - a transporting device for transporting the processed fibreboard from the plane base to the storage device.