The invention relates to a developer concentrate which comprises water, at least one agent which is alkaline in water and an amphoteric surfactant and additionally at least one anionic surfactant, at least one complexing agent, at least one aminoalcohol and at least one N-alkoxylated mono- or polyfunctional amine. A ready-to-use developer can be prepared from this concentrate by dilution with tap water advantageously in the ratio of from 1:0.5 to 1:10, preferably in the ratio of from 1:2 to 1:6. The developer or the replenisher is preferably used in the production of printing plates.