A diffuser which straightens the flow of air issuing from a centrifugal compressor in a turbine engine is provided. The diffuser having a cylindrical shape and including a first part having the form of two substantially parallel discs extending substantially radially relative to the axis of symmetry of the diffuser, a second bent part, and a third part intended to open out into a downstream cavity, positioned downstream of the diffuser and fed with air issuing from the compressor. The first part is traversed by a plurality of channels distributed evenly over its circumference and opening out on its downstream face so as to bring the air contained in the downstream cavity into communication with a bleed cavity situated upstream of the diffuser.