A method for producing aromatic hydrocarbons, the method comprising: a step of performing a cracking reforming reaction by bringing a feedstock having a 10 vol% distillation temperature of 140°C or higher and a 90 vol% distillation temperature of 380°C or lower, into contact, in gas phase, with a catalyst for monocyclic aromatic hydrocarbon production to cause the feedstock to react with the catalyst, and thereby obtaining a product including monocyclic aromatic hydrocarbons having 6 to 8 carbon numbers and a heavy oil fraction having 9 or more carbon numbers; a step of separating the product by separating respectively gas components and a liquid fraction from the product obtained from the cracking reforming reaction step, and thereafter separating the liquid fraction into a LPG fraction, a fraction containing monocyclic aromatic hydrocarbons having 6 to 8 carbon numbers, and a heavy oil fraction having 9 or more carbon numbers; a step of purifying the monocyclic aromatic hydrocarbons having 6 to 8 carbon numbers by separating the fraction containing monocyclic aromatic hydrocarbons having 6 to 8 carbon numbers into respective components of benzene/toluene/xylene, and thereafter purifying and collecting the respective components of benzene/toluene/xylene; and a step of collecting naphthalene compounds by separating the heavy oil fraction into a fraction containing naphthalene compounds and a fraction not containing the naphthalene compounds, and thereafter purifying and collecting the naphthalene compounds, wherein in the cracking reforming reaction, polycyclic aromatic hydrocarbons included in the feedstock are partially hydrogenated by a hydrogen transfer reaction from saturated hydrocarbons by using the saturated hydrocarbons included in the feedstock as a hydrogen donating source, and the polycyclic aromatic hydrocarbons are converted to monocyclic aromatic hydrocarbons by ring-opening, wherein the catalyst consists of a crystalline aluminosilicate or the catalyst contains a crystalline aluminosilicate and one or more of phosphorus, boron, gallium, and zinc, wherein a reaction temperature employed when the feedstock is allowed to react with the catalyst for monocyclic aromatic hydrocarbon production in the cracking reforming reaction is from 400°C to 650°C, wherein a reaction pressure employed when the feedstock is allowed to react with the catalyst for monocyclic aromatic hydrocarbon production in the cracking reforming reaction is from 0.1 MPaG to 1.5 MPaG, and wherein a contact time in which the feedstock is brought into contact with the catalyst for monocyclic aromatic hydrocarbon production in the cracking reforming reaction is from 5 seconds to 150 seconds. a step of performing a cracking reforming reaction by bringing a feedstock having a 10 vol% distillation temperature of 140°C or higher and a 90 vol% distillation temperature of 380°C or lower, into contact, in gas phase, with a catalyst for monocyclic aromatic hydrocarbon production to cause the feedstock to react with the catalyst, and thereby obtaining a product including monocyclic aromatic hydrocarbons having 6 to 8 carbon numbers and a heavy oil fraction having 9 or more carbon numbers; a step of separating the product by separating respectively gas components and a liquid fraction from the product obtained from the cracking reforming reaction step, and thereafter separating the liquid fraction into a LPG fraction, a fraction containing monocyclic aromatic hydrocarbons having 6 to 8 carbon numbers, and a heavy oil fraction having 9 or more carbon numbers; a step of purifying the monocyclic aromatic hydrocarbons having 6 to 8 carbon numbers by separating the fraction containing monocyclic aromatic hydrocarbons having 6 to 8 carbon numbers into respective components of benzene/toluene/xylene, and thereafter purifying and collecting the respective components of benzene/toluene/xylene; and a step of collecting naphthalene compounds by separating the heavy oil fraction into a fraction containing naphthalene compounds and a fraction not containing the naphthalene compounds, and thereafter purifying and collecting the naphthalene compounds, wherein in the cracking reforming reaction, polycyclic aromatic hydrocarbons included in the feedstock are partially hydrogenated by a hydrogen transfer reaction from saturated hydrocarbons by using the saturated hydrocarbons included in the feedstock as a hydrogen donating source, and the polycyclic aromatic hydrocarbons are converted to monocyclic aromatic hydrocarbons by ring-opening, wherein the catalyst consists of a crystalline aluminosilicate or the catalyst contains a crystalline aluminosilicate and one or more of phosphorus, boron, gallium, and zinc, wherein a reaction temperature employed when the feedstock is allowed to react with the catalyst for monocyclic aromatic hydrocarbon production in the cracking reforming reaction is from 400°C to 650°C, wherein a reaction pressure employed when the feedstock is allowed to react with the catalyst for monocyclic aromatic hydrocarbon production in the cracking reforming reaction is from 0.1 MPaG to 1.5 MPaG, and wherein a contact time in which the feedstock is brought into contact with the catalyst for monocyclic aromatic hydrocarbon production in the cracking reforming reaction is from 5 seconds to 150 seconds.