[Problem] To provide a cooling device for an outdoor unit wherein drain water is not discharged in an extremely off-centered manner as a result of the inclination of a rotor bucket with respect to the axial direction of the rotational axis. [Solution] A cooling device for an outdoor unit using air-conditioning drain water, wherein: a rotor bucket (13A) is formed by connecting side wall surfaces in the lengthwise direction so as to have a V-shaped cross section, with both ends thereof being closed off by wall surfaces (13B); the base part (14A) of an L-shaped member (14), in which the base part and a protruding piece (14B) are integrally formed, is secured to the wall surface at respective ends of the rotor bucket; a V-shaped receiving fixture (10A-3) is secured to the inner end surface at respective ends of a casing (10A); the protruding pieces of the L-shaped member are mounted in the receiving fixtures, with the lower end edges of the protruding pieces constituting the rotational axis of the rotor bucket. I
