In a method for producing powdered iron oxide by oxidizing roasting an iron chloride solution, the pH-value of the crude iron chloride solution is adjusted to 2,5 to 4,5, the solution is subjected to a mechanical treatment in order to obtain a solution whose pH-value is not less than 1,5 and which contains insoluble Fe³⁺compounds in an amount of 0,01 to 0,1 % by weight, being calculated as Fe. The insolubles are separated from the solution and the resulting filtrate or purified solution is then roasted and oxidized in order to produce powdered iron oxide having a P content of not more than 0,005 % by weight.