PROBLEM TO BE SOLVED: To obtain a hydroponics mat which has an excellent performance and is excellent on environments and inexpensive by dehydrating a slurry comprising a specific composition and then drying the dehydrated slurry to give a specific density. SOLUTION: This mat used for hydroponics and having a density of 0.02-0.30 g/cm3 is obtained by dehydrating a slurry consisting mainly of cellulose fibers and having a Canada standard freeness(CSF) of >=550 ml by the use of a mesh and then drying the dehydrated slurry. Therein, the cellulose fibers are preferably cellulose fibers subjected to at least one treatment selected from a water- repelling treatment, a water-resisting treatment and a curing treatment. The cellulose fibers are preferably further subjected to a curling treatment. It is preferable that a raw material for the cellulose fibers is waste paper.
