<p>A centrifugal blower configured to minimize a reduction in the fan efficiency caused by a leakage flow at the gap between the bell mouth and the shroud. A centrifugal blower (51) is provided with an impeller (23) and a bell mouth (25). The bell mouth (25) has wall sections (27) which are arranged on the outer peripheral surface (25s) thereof in the circumferential direction at predetermined intervals and which are upstanding from the outer peripheral surface (25s). The wall sections (27) extend along the outer peripheral surface (25s) from the front (F) side to the rear (R) side in the axial direction (A) so as to be substantially parallel to the axial direction (A) and to the radial direction of the bell mouth (25).</p>
