PURPOSE: To provide the needle thread supplying device of a sewing machine capable of preventing the tangling and detachment of thread to/from a needle thread feed roller and smoothly feeding the needle thread.

CONSTITUTION: The entrance position 5 of the needle thread entering a needle thread supply roller 1 is brought closer to the nip position of the needle thread feed roller 1, a needle thread guiding plate 4 on which the thread discharge window 4a' of a size sufficient for discharging the cut and stored needle thread is formed is provided on the downstream side of the needle thread feed roller 1 and a thread tangling preventing plate 6 for preventing the needle thread stored on both sides of the thread discharge window 4a' from being moved to the side of gears 2a and 2b at the end of the needle thread feed roller is provided.