To provide a sludge scraper arranged in a precipitating pond where sludge contained in accepted water precipitates on the bottom part of the pond and scraping the sludge precipitated on the bottom part of the pond by flight plates and preventing the dislocation of an endless chain from a rotating wheel without sacrificing the scraping ability of the sludge.

The endless chain 31 has a plurality of coupling pins 313 and a plurality of link members 310 having through-holes and is constituted by coupling the link members 310 themselves by passing the coupling pins 313 through the through-holes of the link members 310 themselves. In predetermined coupling pins more than the number of the flight plates 32 attached to the endless chain 31 out of the plurality of coupling pins 313, the one side end parts thereof are spaced apart from a guide member 342 in a radial direction of the coupling pins 313 and protrude from the link members 310 to a position overlapping the guide member 342 when viewing from above at positions where guide members 342, 352, 362, 372 are arranged.