To provide a collected dust return-back equipment from a mold shakeout device so as to return bentonite fine powder which is generated at the position of the mold shakeout device and collected, into recovered sand without any trouble.

In this collected dust return-back device, a cushion hopper 13 is communicated with the lower part of a dust hopper 11 of a dust collector 9 communicated with the mold shakeout device through a first discharging device 12. The lower part of the cushion hopper 13 is faced to a recovered sand conveyor 4 succeeded just after the mold shakeout device through a second discharging device 14. Then, a sand shifting confirmation sensor 16 is arranged on the recovered sand conveyor 4 and also, the sand shifting confirmation sensor 16 and the second discharging device 14 are electrically connected through a controller 17.