The amount of arsenic (As) in the earth increases every day and adversely affects the life of all living beings,including human health. Therefore, studies on the development of As determination methods are graduallygaining importance. The foundation of the Diffusive Gradients in Thin Film (DGT) technique addressed in thisstudy is based on the diffusion process. The analyte to be determined passes through different layers in the DGTunit and reaches the adsorber gel layer. In the study presented, the gel obtained from iron (III) oxide (Fe2O3) wasused as the adsorber layer. The use of the DGT technique in the amount determination of As(III) and As(V)species in the aqueous medium was examined and all the measurements performed during the experimentalstudies were observed to be made with an ICP-MS device. Different parameters were evaluated in terms ofdifferent pH values, ionic strength effects, gel layer thickness and the effects of the eluent materials and the mostsuitable working conditions were determined.