A lubricant oil for a refrigeration machine, and refrigeration machine, said refrigeration machine being of the type that operates with a refrigerant consisting of at least one component of the HC (hydrocarbon) group, the lubricant oil consisting of an alkylbenzene oil containing at least 80% by weight of alkylbenzene having a molecular weight of 120-288 and having a viscosity between about 3.0 and 7.0 cSt at a temperature of 40° C. and the lubricant composition consisting of said alkylbenzene oil and until about 8% by weight of one or more additives selected from a group consisting of improvers of oxidation resistance and thermal stability, corrosion inhibitors, metal inactivators, lubricity additives, viscosity index improvers, reducers of fluidity and flocculation point, detergents, dispersants, antifoaming agents, antiwear agents and extreme pressure resistant additives.