An anastigmat Korsch telescope with three aspherical mirrors comprising at least one first concave mirror having a central aperture (Ac), a second convex mirror arranged in front of the first mirror, a third concave mirror, at least one first deflecting mirror and a detector, - the mirrors being arranged so that the first mirror and the second mirror form an intermediate image of an object at infinity, the image being located between the second mirror and the third mirror, the third mirror forming a final image of this intermediate image in the focal plane of the telescope wherein the detector is placed, the telescope further comprising: - a bearing structure having a first face to which the first mirror is attached, - a hollow structure of a shape elongated in a direction substantially perpendicular to the plane (P AC) of the central aperture (Ac), limited by walls, attached to the inside of which are the second mirror in a portion of the hollow structure located in front of the first mirror, and at least one other mirror (M3, MR1) selected from the third mirror and the at least one deflecting mirror, said walls having at least one first aperture so as to allow a light beam coming from the object, originating from the first mirror and heading toward the second mirror, to pass through, - said bearing structure further comprising means of attachment of the hollow structure to said bearing structure, - the bearing structure having a hollow front portion traversing the central aperture (Ac) and surrounding a portion of the hollow structure, said means of attachment being arranged at the level of said front portion of the bearing structure. - the mirrors being arranged so that the first mirror and the second mirror form an intermediate image of an object at infinity, the image being located between the second mirror and the third mirror, the third mirror forming a final image of this intermediate image in the focal plane of the telescope wherein the detector is placed, the telescope further comprising: - a bearing structure having a first face to which the first mirror is attached, - a hollow structure of a shape elongated in a direction substantially perpendicular to the plane (P AC) of the central aperture (Ac), limited by walls, attached to the inside of which are the second mirror in a portion of the hollow structure located in front of the first mirror, and at least one other mirror (M3, MR1) selected from the third mirror and the at least one deflecting mirror, said walls having at least one first aperture so as to allow a light beam coming from the object, originating from the first mirror and heading toward the second mirror, to pass through, - said bearing structure further comprising means of attachment of the hollow structure to said bearing structure, - the bearing structure having a hollow front portion traversing the central aperture (Ac) and surrounding a portion of the hollow structure, said means of attachment being arranged at the level of said front portion of the bearing structure. - a bearing structure having a first face to which the first mirror is attached, - a hollow structure of a shape elongated in a direction substantially perpendicular to the plane (P AC) of the central aperture (Ac), limited by walls, attached to the inside of which are the second mirror in a portion of the hollow structure located in front of the first mirror, and at least one other mirror (M3, MR1) selected from the third mirror and the at least one deflecting mirror, said walls having at least one first aperture so as to allow a light beam coming from the object, originating from the first mirror and heading toward the second mirror, to pass through, - said bearing structure further comprising means of attachment of the hollow structure to said bearing structure, - the bearing structure having a hollow front portion traversing the central aperture (Ac) and surrounding a portion of the hollow structure, said means of attachment being arranged at the level of said front portion of the bearing structure.