To provide a catch basin with a backflow prevention valve that is easy to maintain, capable of reliably preventing only the reverse flow of drainage without causing clogging of drainage by foreign matters, etc.SOLUTION: There is provided a catch basin comprising an inlet, a backflow prevention valve to prevent the backflow of wastewater into the inlet, an outlet, an invert section connecting the inlet and outlet, and an inspection port opening above the invert section. The backflow prevention valve consists of a valve pipe attached to the inner wall surface or the inlet of the catch basin, and a valve body oscillatingly supported at the upper end on the downstream side of the valve pipe. The downstream opening end of the valve pipe is formed so as to incline from the downstream side to the upstream side as it goes from the upper part to the lower part.SELECTED DRAWING: Figure 1