The present invention provides a method for producing hydrogen peroxide,
comprising the steps of: alternately reducing and oxidizing a working
solution containing anthraquinone compounds as a reaction medium, wherein
a mixture of alkyl-substituted anthraquinones and alkyl-substituted
tetrahydroanthraquinones in a molar ratio of from 2:1 to 8:1 is used as
the anthraquinone compounds in the working solution, in the reduction
step all of the tetrahydroanthraquinones and some or all of the
anthraquinones in the working solution are reduced; and keeping the
content of alkyl-substituted anthrahydroquinones in the working solution
after the reduction step and before the oxidation step higher than the
content of alkyl-substituted tetrahydroanthrahydroquinones, wherein
ethylanthraquinone and ethyltetrahydroanthraquinone are used as
anthraquinone compounds in the working solution in a total proportion of
both of from 10 to 45 mol % of all of the anthraquinone compounds in the
working solution.