A method for manufacturing a low-oxygen copper wire is provided, in which a dehydrogenating treatment can be performed without requiring a long moving distance of molten copper, and the generation of holes in solidification is suppressed, whereby high quality low-oxygen copper wire can be obtained having superior surface quality. The method for continuously manufacturing ingots of low-oxygen copper from molten copper includes a step of performing combustion in a reducing atmosphere in a melting furnace so as to produce molten copper; a step of sealing the molten copper in a non-oxidizing atmosphere in a casting trough; a step of transferring the molten copper to a tundish by using the casting trough; a degassing step of passing the molten copper through a degasser provided in the casting trough so as to dehydrogenate the molten copper; a step of continuously feeding the molten copper to a continuous casting machine so as to continuously produce cast copper; and a step of cutting the cast copper into a predetermined length.