Abstract: This invention relates to a centrifugal sewage pump of a torque flow type having a hollow depressed backward curve in front of a shroud of an impeller, in which an outer periphery portion of a vane is projected into a water passage for the purpose of improving a pumping head and pump efficiency and simultaneously for the purpose of avoiding pump clogging caused by fibriform solid matter adhering to the front edge of the vane. In order further securely to avoid clogging of the pump due to fibriform solid matter, a cutter plate or guide plate is provided alongside the flow line, to remove fibriform solid matter from said vane front edge, so that they can be positively discharged outward. By providing a shoulder on the outer periphery of the vane projecting into the water passage, the pump permits free adjustment of pumping head without changing pump rotational speed.