To provide a dryer which requires a short drying time, can save space, can be small-sized, and gives dried products usable in a wide range by sufficiently dewatering objects to be dried attached to a net by a compression dewatering mechanism and drying the objects in the form of a film having a small drying depth.

A resin-made net 1 with sludge attached thereto is conveyed by many sending rollers 18 so that it goes around until the completion of drying. First, wastewater with floating sludge is supplied at a supply port 2 for materials to be treated, and sludge deposited on the meshes of a net 5 is compressed and dewatered together with the net 5 by compression rollers 4. Next, the conveying speed is controlled so that the drying is completed during the tour through a heat-generation evaporation chamber 15, and thus the drying of the sludge deposited on the net 1 is completed. Then, the dried hard sludge tightly adhering to the meshes of the net is scraped down by the swinging from side to side at a roller 10 and by the scraping with a roller brush 8. Thus, the dried sludge falls through a dried sludge take-out port 12 and is collected in a dried sludge receptacle 13.