To make it possible to circulate the entire part of water in water tanks all over and to maintain water quality for a long time without the stagnation of suspended matter or precipitate within the water tanks.

The base surfaces of the water tanks 14 of the cut flower exhibition device for circulating and supplying the cold water to the water tanks 14 (14a, 14b and 14c are representatively expressed) are graded from in flow ports 19 toward outflow ports 20. The device is constituted by connecting a plurality of the water tanks 14 constituted in the manner described above in series via bypass pipelines 22 opened in the upper parts. The water tank 14 provided with the inflow port 19c and outflow port 20c of at least the final stage in the water tank 14 groups to be connected is interposed in the device and the bottom of the water tank is provided with a valve for discharging the precipitate.