A turbomachine comprising an annular combustion chamber (40) with injection orifices (44); a centrifugal compressor (10) having a centrifugal downstream stage and an annular diffuser (20) comprising: a radially-oriented upstream portion (21)with diffusion passages (22) connected to the outlet of the compressor and an elbow-shaped intermediate portion (24)and a downstream portion (25) comprising a series of flow-straightening vanes (26) and inclined relative to the axis (A) of the turbomachine. In the section plane containing the axis (A) of the turbomachine and passing via the center (C) of one of said injection orifices (44), the curvilinear abscissa distance along a flow line (L) between the middle (0) of the flow path at the trailing edges of the flow-straightening vanes (26) and said center (C) is greater than or equal to three times the height (h) of said flow path.