Method for producing a pale-colored soy sauce, includes subjecting a soy sauce to a permeation treatment using a nano filtration membrane module having a small pore size to give a first permeated liquid and an unpermeated liquid then subjecting the unpermeated liquid to a permeation treatment using a nano filtration membrane module having a larger pore size than that of the nano filtration membrane module to give a second permeated liquid (B) and combining both permeated liquids to obtain the pale-colored soy sauce. Preferably, two kinds of nano filtration membrane modules having different salt rejection percentages are used, such that the module having a small pore size has an a % salt rejection and the other module has a b % salt rejection, and a and b satisfy the following formulae: (1) a>b, (2) 40%≦a≦70%, (3) 5%≦b≦40%, and (4) 22≦a−b≦65.
