To provide a motive power take-off device capable of optimally setting position of a second PTO shaft in relation to a working machine.

This motive power take-off device is installed in a tractor 1 having an axle 13 of one side in the fore and aft direction of a car body supported by an axle case 11 rockably suspended around a center pin 12 along the fore and aft direction of a machine body so that the motive power is transmitted from a transmission to at least the other side axle 9 and provided with a first PTO shaft 55 under the transmission. In this motive power take-off device, a second PTO shaft 56 is supported by the axle case 11 at a position offset downward from the center pin 12, and both sides of the ends of the second PTO shaft 56 are extended outward and inward of the machine body, and the inside end of the second PTO shaft 56 in relation to the machine body is connected to the first PTO shaft 55 through universal joints 70, 71.