An outdoor unit according to the present invention includes: a casing; and a heat exchanger accommodated in the casing. The casing includes a bottom panel on a bottom surface of the casing. The bottom panel includes: a first bottom plate portion formed below the heat exchanger; and a second bottom plate portion formed on the bottom panel at a portion other than the first bottom plate portion. A lower end of the heat exchanger is arranged at a position above any point on an upper surface of the first bottom plate portion and below any point on an upper surface of the second bottom plate portion.