In a method of manufacturing a radiator, the blade of a carving tool is applied at a specific angle to the surface of a metal plate with a high coefficient of thermal conductivity, the carving tool is advanced while the angle is maintained, and the surface of the metal plate is carved out to form plate-shaped heat-radiating fins vertically upward. A radiator is manufactured in which a plurality of heat-radiating fins are integrally formed vertically upward at a specific pitch from a single metal plate by repeating a step in which the carving tool is retracted at a specific pitch, the metal plate is carved out, and a heat-radiating fin is formed. A radiator that has high radiation efficiency and is highly safe during handling can be manufactured at low cost.