A disinfectant comprising the following (a), (b), (c) and (d), but no other microbicidal disinfecting agents intended for microbicidal disinfection:(a) 40 to 90% (w/w) of ethanol, isopropyl alcohol or a mixture thereof; (b) 0.1 to 2% (w/w) of lactic acid; (c) 0.01 to 2% (w/w) of citric acid; and (d) 0.001 to 0.1% (w/w) of a zinc-containing compound which releases zinc ion in solution, relative to the whole disinfectant.