A method for preparing hydroxylamine is provided that includes the steps of pretreating an acidic buffer solution; and reducing nitrate ions in the acidic buffer solution with hydrogen to give hydroxylamine in the presence of catalysts, wherein the pretreatment is performed by adding a precipitant represented by formula to the acidic buffer solution,aM6. The air input connector is configured and arranged to receive air from a pressurized air source. An absorbent pad is provided at a central region on the surface of the adhesive layer to obtain a first-aid adhesive tape.