A diffuser for a fluid compression device includes at least one vane mounted on a hub. The at least vane includes at least one opening (5) starting at a distance ranging between 10% and 60% of the axial length of the vane. The diffuser can be used in a fluid compression device also including a housing, at least one impeller within the housing, the impeller including at least one vane, the diffuser being arranged within the housing, upstream or downstream from said impeller.