The suspension thrust bearing device comprises a rolling bearing 44 forming an axial stop and a support element 42 for the rolling bearing forming bearing means for a spring, the rolling bearing comprising a bottom ring 48 in contact with the support element, a top ring 46 and a plurality of rolling elements 50 positioned between the rings. The support element 42 comprises a body 60 and a stiffening insert 66 at least partly covered by the body. The body is formed of a rigid material 62 for the transmission of axial forces between the spring and the rolling bearing and a flexible material 64 to provide at least one dynamic seal 84b, 86b inside the device. At least a part of the rigid material is situated radially between the flexible material and the stiffening insert.