Outdoor unit for air conditioner

An outdoor unit for an air conditioner, comprising: a heat exchanger disposed inside a housing; and a bottom plate of the housing, including, a bottom plate portion, a flange formed by upwardly folding back an edge of the bottom plate portion, a drainage hole penetrating the bottom plate portion and configured to discharge water, a plurality of mounting bases protruding upwardly from the bottom plate portion and supporting a lower end of the heat exchanger by upper surfaces thereof, and a drainage conduit provided in contact with the mounting bases and inclining downward toward the drainage hole, wherein a portion of the bottom plate portion positioned between at least one of the plurality of the mounting bases and the flange includes an inclined portion which is inclined toward the drainage conduit in a longitudinal direction of the flange.