A melt spinning apparatus particularly applicable to a multifilament spinning for pitch based carbon fibers. The melt spinning apparatus is provided in which a flow uniforming member is attached to a central part on a spinning side of a spinneret having circularly or concentrically arranged nozzles, the flow uniforming member having a sectional diameter at least 3 mm smaller than the diameter of the innermost row of nozzles and a length not smaller than 2 cm. The apparatus is provided with a cooling means as an outer peripheral portion below a spinning pack having an annular blowing port for blowing a cooling gas toward the spun filaments. A gap is provided between the spinning pack and the cooling means and is sealed with a heat insulator.