For known forestry harvesters with some kinds of hard or tough trees, there may be times where the limbs cannot be cut off and the tree is not delimbed. In these cases, the tree needs to be retracted and advanced again to push limbs against the upper cutter and the side cutters to delimb the tree. However, the delimbing may not be successful and the same operation will be repeated. Repetition of this operation causes damage to the surface of the tree and it can take increased time for delimbing depending on the kind of tree. The present invention provides a forestry harvester for delimbing a tree with an angular upper cutter and side cutters while advancing the tree by feed rollers, wherein when the feeding of the tree is stopped due to being incapable of cutting the limbs off, the angle-shaped upper cutter and the side cutters are moved relative to the tree with rotation of the feed rollers stopped to cut off the limbs of the tree therewith. The forestry harvester comprises a feed unit (1 or 100) including a pair of left-hand and right-hand clamp arms (8, 9 or 108, 109) and feed means (20 or 120), a chain saw box (22a) having a power chain saw (22), a delimbing unit (2) including an angle-shaped upper cutter (52) and a pair of cutter arms (26， 26) each having a side cutter (25), guide mechanism for guiding the delimbing unit for forward and rearward movement of the delimbing unit relative to the feed unit, and a hydraulic cylinder actuated to move the delimbing unit (2) toward and away from the feed unit (1 or 100).
