The present invention addresses the problem of providing an effective means for suppressing microbial growth after unsealing of a concentrated-type acidic milk beverage which includes milk. Through the present invention, there is provided a concentrated-type acidic milk beverage characterized by containing (A) milk, (B) ε-polylysine, and (C) at least one species selected from benzoic acid, a parahydroxybenzoic acid ester, and a salt thereof, the nonfat milk solid content being 1.5-4.5 wt%, and the Brix value being 40-60.