A process for producing an oxygen absorbing agent includes treating an alloy with an aqueous solution of an acid or an alkali, the alloy including at least one transition metal selected from the group consisting of manganese, iron, platinum, and copper group metals and at least one metal selected from the group consisting of aluminum, zinc, tin, lead, magnesium, and silicon to elute and remove at least a part of the component; and subjecting the alloy obtained by removing at least a part of the component in the alloy to treatment with an aqueous solution of a salt of an inorganic acid or a salt of an organic acid that can form a salt with the transition metal as the component, to form a metal salt in at least a part of the surface of the alloy.