Abstract: The invention relates to a self-feeding wood chunker having cutting instruments (1, 2) rotating in opposite directions but with the same speed, which have, on surfaces facing one another, at least one cutting blade (3.sub.1, 3.sub.2 and 4.sub.1, 4.sub.2), the blades being curved in the direction of rotation such that the leading part (3a, 4a) thereof is nearer to the periphery of the respective cutting instrument and that the trailing part (3a, 4a) thereof is nearer to the axis of rotation (1a, 2a) of the respective cutting instrument. According to the invention, the cutting instruments (1, 2) are arranged with the axes of rotation (1a, 1b) displaced a definite distance (B) from one another.