To provide an outdoor unit for an air conditioner in which attachment and detachment of an electrical equipment box are safely carried out while a large-sized electrical equipment box is positively supported.

To form a rotating means for rotating the electrical equipment box 5 with respect to a casing 10 so that H1H2 is satisfied when a shaft length of one rotary shaft (a first rotary shaft 73) is H1 and a shaft length of the other rotary shaft (a second rotary shaft 83) is H2.