A boring machine (10,300) for making a trench in soil, the machine comprising a frame (12,312) extending along a longitudinal direction, said frame (12,312) having a bottom end (12a,312a), the boring machine having a boring device (20,320) mounted at the bottom end (12a,312a) of the frame (12,312), the boring device (20,320) comprising: - a first boring member that is rotatable about a first axis of rotation, the first axis of rotation being transverse to the longitudinal direction of the frame; - a first motor configured to drive rotation of the first boring member about the first axis of rotation; - a second boring member rotatable about a second axis of rotation, the second axis of rotation being stationary relative to the first axis of rotation; - a second motor configured to drive the second boring member in rotation about the second axis of rotation; - a third boring member rotatable about a third axis of rotation, the third axis of rotation being spaced apart from and parallel to the first axis of rotation; - a third motor configured to drive the third boring member in rotation about the third axis of rotation; - a fourth boring member that is rotatable about a fourth axis of rotation, the fourth axis of rotation being stationary relative to the first, second, and third axes of rotation (X1,X2,X3); and - a fourth motor configured to drive the fourth boring member in rotation about the fourth axis of rotation, the first, second, third, and fourth axes of rotation (X1,X2,X3,X4) lying substantially in a common plane that is transverse to the longitudinal direction of the frame; and - a support that is mounted at the bottom end of the frame and that carries the first, second, third, and fourth boring members (30,50,60,70), together with the first, second, third, and fourth motors (32,52,62,72). - a first boring member that is rotatable about a first axis of rotation, the first axis of rotation being transverse to the longitudinal direction of the frame; - a first motor configured to drive rotation of the first boring member about the first axis of rotation; - a second boring member rotatable about a second axis of rotation, the second axis of rotation being stationary relative to the first axis of rotation; - a second motor configured to drive the second boring member in rotation about the second axis of rotation; - a third boring member rotatable about a third axis of rotation, the third axis of rotation being spaced apart from and parallel to the first axis of rotation; - a third motor configured to drive the third boring member in rotation about the third axis of rotation; - a fourth boring member that is rotatable about a fourth axis of rotation, the fourth axis of rotation being stationary relative to the first, second, and third axes of rotation (X1,X2,X3); and - a fourth motor configured to drive the fourth boring member in rotation about the fourth axis of rotation, the first, second, third, and fourth axes of rotation (X1,X2,X3,X4) lying substantially in a common plane that is transverse to the longitudinal direction of the frame; and - a support that is mounted at the bottom end of the frame and that carries the first, second, third, and fourth boring members (30,50,60,70), together with the first, second, third, and fourth motors (32,52,62,72).