To carry out the dehydration easily, and improve the removing efficiency of suspended particles.

Suspended matters contained in wastewater are attracted removed by utilizing the static force generated by charged particles 30, and suspended matters and a water content adhered on the charged particles 30 are dehydrated and separated on a screen belt 33 in the constitution of a device. The upstream side of a screen belt 33 on which the charged particles 30 with suspended matters adhered on is formed into a low speed zone 34 blowing air at low speed, while its downstream side is set to be a high speed zone 35 blowing air at high speed, and a water recovery tank 36 is set on the lower section of the low speed zone 34, while a suspended matter recovery tank 37 is set on the lower section of the high speed zone 35.