Abstract: An arrangement (1) and a method for preventing the spread of microbes to a person (2) and/or from the person (2) in an indoor environment (3). The arrangement (1) comprises at least one ion-producing element (4) with a tip (5) that emits negative ions and is connectable to a power source (6) and is configured to emit a conical ion beam (7) containing negative ions as a negative direct voltage is supplied to said ion-emitting tip (5) from the power source (6), said tip (5) emitting negative ions being installable in the indoor environment (3), such as above the person (2). The orientation of the tip (5) emitting negative ions is adjustable in order to direct the ion beam (7) towards the person (2) in the indoor environment (3).