To obtain a detergent for automatic dish washers which has excellent detergency against various stains on dishes, and simultaneously, no adhesion of scales thereto.

The detergent composition for automatic dish washers comprises 0.5-30 wt.% monopotassium hydrogen persulfate as component (A), 0.1-15 wt.% surface active agent as component (B); and 0.1-50 wt.% silicate as component (C). It is preferred that the composition further comprises a carbonate as component (D) and a hydroxypolycarboxylic acid or its salt as component (E). Moreover, it is more preferred that the composition has a component (A) to component (C) ratio of 1/3 to 1/10. This detergent composition has excellent detergency against various stains on dishes, and simultaneously, reduced adhesion of scales thereto.