To provide a liquid feeding and flow regulating mechanism which is capable of generating the flow of a washing liquid nearly uniform over the entire liquid depth and supplying this flow to a washing tank and has an excellent flow regulating effect.

A flow regulating unit 13 having a first flow regulating plate 21 of a large water flow resistance and a second flow regulating plate 22 of a small water flow resistance is mounted within a casing 12 of a box shape opened only at its front end face 14 as an outflow port for a washing liquid, by which a hermetically closed liquid feed chamber 27 is formed behind the flow regulating unit 13. The washing liquid 5 is put into a pressurized state and is passed from the liquid feed chamber 27 into the flow regulating unit 13, by which the velocity of flow uniform over the entire liquid depth is obtd. with the first flow regulating plate 21. The turbulence of the washing liquid 5 is relieved by the second flow regulating plate 22 and is approximated to the uniform flow.