A regenerative fluid machine having guide vanes on a flow channel wall is disclosed. The regenerative fluid machine includes a circular plate-shaped impeller having a plurality of vanes radially formed on an outer circumference thereof at regular intervals, casings in which the impeller is housed, and flow channels, each of which has a suction hole and a discharge hole in opposite ends thereof, and which are circumferentially disposed within the casings so as to face the vanes. The plurality of guide vanes having an inclined angle (θ) with respect to a radial direction protrude from the flow channel wall in a rotational direction of the impeller so that a relative inflow angle (β) of the fluid introduced into the impeller grooves is increased and thus an absolute inflow angle (α) is decreased.