A stump extraction device (42) comprising two opposite jaws (20, 24), two opposite cutting blades (22, 26) connected as extensions of the jaws (20, 24), a rotation device (14), and fixing elements (18) which are fixed to the rotation device (14) and by means of which the stump extraction device (42) can be rigidly fixed to a desired object. The rotation device (14) is configured to rotate the body (10) and the jaws (20, 24) with respect to the fixing elements (18). A moving working machine (44) comprises the stump extraction device (42) and a knuckle boom assembly (46), to an end of which the stump extraction device (42) is rigidly connected. The moving working machine (44) may be a crawler excavator. In a method, roots (56, 58) in the ground (60) are cut off from a stump (54) by closing the jaws (20, 24) and the stump (54) is separated from the roots (56, 58) by lifting the stump extraction device (42) by means of the knuckle boom assembly (46).
