A device for determining residual stresses of at least one zone of an object (E), including: - an X-ray or neutron source (S) emitting an incident beam along an incident direction (Z), - means configured to set a non-zero angle (ψ 0 ) between a direction (N) normal to a surface of the object (E) and the incident direction (Z), the incident beam being diffracted by the zone of the object (E) into a plurality of rays (FD), each ray (FD n ) being diffracted with a Bragg angle (2θ), to each beam (FD n ) corresponding a diffraction vector (ND n ) which is the bisector between the incident beam and said diffracted ray (FD n ), said diffraction vector having a tilt angle (ψ n ) relative to said normal direction (N), - a detection device (DD) including an opening (O) aligned with the incident direction and including means provided with at least one active surface to simultaneously intercept the diffracted rays for at least two different values of the Bragg angle (2θ 1 , 2θ 2 ) at two different tilt angles (ψ 1 , ψ 2 ), allowing acquisition of at least one diffraction picture, - the detection device (DD) being disposed relative to the source (S) so that it is between the source (S) and the location provided for the object (E) and the active surface faces the location provided for the object (E), - means (C) for processing said at least one diffraction picture and for determining the residual stresses, characterised in that the processing means are configured to determine two pairs of values of Bragg angle and tilt angle ([2θ 1 , ψ 1 ];([2θ 2 , ψ 2 ]) from the said at least one picture and determine, from said pairs of values, a slope of a function Δ2θ = f(sin 2 ψ) corresponding to the residual stresses of the zone of the object. - an X-ray or neutron source (S) emitting an incident beam along an incident direction (Z), - means configured to set a non-zero angle (ψ 0 ) between a direction (N) normal to a surface of the object (E) and the incident direction (Z), the incident beam being diffracted by the zone of the object (E) into a plurality of rays (FD), each ray (FD n ) being diffracted with a Bragg angle (2θ), to each beam (FD n ) corresponding a diffraction vector (ND n ) which is the bisector between the incident beam and said diffracted ray (FD n ), said diffraction vector having a tilt angle (ψ n ) relative to said normal direction (N), - a detection device (DD) including an opening (O) aligned with the incident direction and including means provided with at least one active surface to simultaneously intercept the diffracted rays for at least two different values of the Bragg angle (2θ 1 , 2θ 2 ) at two different tilt angles (ψ 1 , ψ 2 ), allowing acquisition of at least one diffraction picture, - the detection device (DD) being disposed relative to the source (S) so that it is between the source (S) and the location provided for the object (E) and the active surface faces the location provided for the object (E), - means (C) for processing said at least one diffraction picture and for determining the residual stresses, characterised in that the processing means are configured to determine two pairs of values of Bragg angle and tilt angle ([2θ 1 , ψ 1 ];([2θ 2 , ψ 2 ]) from the said at least one picture and determine, from said pairs of values, a slope of a function Δ2θ = f(sin 2 ψ) corresponding to the residual stresses of the zone of the object. <EOS>