PROBLEM TO BE SOLVED: To enable a worker to fell various kinds of trees in different conditions safely and automatically while directly viewing the target tree for felling in a state in which the worker is away from the trees.SOLUTION: A felling system 10 comprises: a cutting tool 11 a manipulator 12 for operating the cutting tool 11 movably a tree information detection device 13 for automatically collecting the information of a tree T and a control device 14 for controlling operation of the manipulator 12 to cut a trunk of the tree T with the cutting tool 11. The tree information detection device 13 comprises: trunk specifying means 50 for specifying an existence range of the tree to measure a diameter of the tree and felling direction determination means 51 for obtaining an inclination of the trunk and a distribution of the branches of the tree T to estimate the direction to which the centroid of the tree T exists, and determine the felling direction of the tree T. The control device 14, from the detected result in the tree information detection device 13, automatically generates movement track of the cutting tool 11 to control the operation of the manipulator 12 so that the cutting tool 11 will move in accordance with the movement track.
