To provide a membrane which can remove in one-liquid system both an inorganic component and an organic component from a filtration membrane used for filtering a mixture containing both the inorganic component and the organic component, can sufficiently exhibit the effect for deterging the filtration membrane, and has high storage stability.

This membrane detergent comprises a sterilizer, a surfactant, a stabilizer and a builder, and is characterized in that the surfactant is an anionic surfactant and in that the builder is ethylenediamine tetraacetate.