A planet carrier for a speed reducer of an aircraft turbomachine, this planet carrier comprising: - a cage carrier with a main axis and comprising a coupling segment centred on this axis and which has axial cage support fingers distributed around the axis, - a cage centred on the axis and comprising two radial annular walls (236, 238) connected to each other by bridges (240a1, 240b1) distributed around the axis, the bridges (240a1, 240b1) being located at the external periphery of the walls (236, 238) and delimiting with the walls (236, 238) an internal cavity of the cage, the bridges (240a1, 240b1) comprising or defining axial housings in which the fingers are mounted, the fingers being connected to the bridges (240a1, 240b1) by connections allowing at least one degree of freedom, one of the walls comprising axially through openings which are axially aligned with axially through openings of the other of the walls, characterised in that the cage comprises two parts (220a, 220b): - a first part comprising one of the walls and the bridges (240a1, 240b1), these bridges (240a1, 240b1) projecting axially from a face of this wall and comprising first axial ends connected to this face and second free axial ends, and - a second part comprising the other of the walls, this wall comprising a face to which the free ends of the bridges (240a1, 240b1) are applied, and in that the two parts (220a, 220b) of the cage are attached together by attachment means which pass through the wall of the second part and are inserted in attachment holes in the bridges (240a1, 240b1). - a cage carrier with a main axis and comprising a coupling segment centred on this axis and which has axial cage support fingers distributed around the axis, - a cage centred on the axis and comprising two radial annular walls (236, 238) connected to each other by bridges (240a1, 240b1) distributed around the axis, the bridges (240a1, 240b1) being located at the external periphery of the walls (236, 238) and delimiting with the walls (236, 238) an internal cavity of the cage, the bridges (240a1, 240b1) comprising or defining axial housings in which the fingers are mounted, the fingers being connected to the bridges (240a1, 240b1) by connections allowing at least one degree of freedom, one of the walls comprising axially through openings which are axially aligned with axially through openings of the other of the walls, characterised in that the cage comprises two parts (220a, 220b): - a first part comprising one of the walls and the bridges (240a1, 240b1), these bridges (240a1, 240b1) projecting axially from a face of this wall and comprising first axial ends connected to this face and second free axial ends, and - a second part comprising the other of the walls, this wall comprising a face to which the free ends of the bridges (240a1, 240b1) are applied, - a first part comprising one of the walls and the bridges (240a1, 240b1), these bridges (240a1, 240b1) projecting axially from a face of this wall and comprising first axial ends connected to this face and second free axial ends, and - a second part comprising the other of the walls, this wall comprising a face to which the free ends of the bridges (240a1, 240b1) are applied, and in that the two parts (220a, 220b) of the cage are attached together by attachment means which pass through the wall of the second part and are inserted in attachment holes in the bridges (240a1, 240b1).