A deoxidizing agent for edible oils, comprising carbonate group-containing magnesium hydroxide particles represented by the following formula (1) and having a BET specific surface area of 80 to 400 m2/g or baked particles thereof, and a method of regenerating an used edible oil by using the deoxidizing agent. MgOH2-xCO30.5x⋅mH2O (x satisfies 0.02 ≦ x ≦ 0.7 and m satisfies 0 ≦ m ≦ 1.)The above deoxidizing agent has excellent deoxidizing capability.