A refrigeration cycle device of the present invention has: a casing (40) that configures the outer contour of an outdoor machine (30), has a machine chamber (M) and a blowing chamber (F) formed therewithin, and has formed an introduction hole (45) for introducing outside air to the machine chamber (M); a partition plate (50) that partitions the interior of the casing (40) in a manner so as to demarcate the machine chamber (M) and the blowing chamber (F); a refrigeration cycle circuit of which at least a portion is disposed in the machine chamber (M) and through which a combustible refrigerant circulates; and a blower (35) disposed in the blowing chamber (F). A blow-through hole (51) connecting from the machine chamber (M) to the blowing chamber (F) is formed at the bottom of the partition plate (50). The outside air introduced from the introduction hole (45) to the machine chamber (M) flows into the blowing chamber (F) through the blow-through hole (51), and by means of the blower (35), is sent to the outside of the casing (40) from a blow-out opening formed at the blowing chamber (F).