A rotating machine comprises a shaft, a casing, at least one main magnetic bearing connected to the shaft for rotatably supporting said shaft inside the casing, at least one first and one second auxiliary rolling bearings positioned between the shaft and the casing to support axial and radial loads, and first and second axial abutment means positioned on the shaft to transmit axial loads to inner rings of the rolling bearings. The machine further comprises a spacer axially positioned between facing faces of the inner rings of said rolling bearings for the transmission of the axial loads between said inner rings, and at least a first axial retaining means positioned on the casing and located axially between facing faces of the outer rings for the transmission of the axial loads between at least one of said outer rings and the casing.