To prevent the knot portion of a veneer from being destructed by a method wherein the veneer is inserted in such a manner that the fiber direction of the knot of the veneer directs to a roll, the veneer conveying force of which is larger than that of the other roll between a pair of the rolls.

One driving roll 1 is connected with an electric motor and further mounted rotatably to a base. On the peripheral surface of the driving roll 1, a large number of a near regular quadrangular pyramid thorns 3 are provided in 4 mm pitch to the rotational direction and 2 mm pitch to the direction normal to the rotational direction. Between the above-mentioned driving roll 1 a rubber roll 5 covered with a urethane rubber 7, which has a rubber hardness of 98° and a radial thickness of 40 mm, as a synthetic rubber, a veneer P is inserted to its fiber direction and, at the same time, to the direction, in which an one point chain line A showing the fiber direction of a knot Q directs to the driving roll 1.