Abstract: In a cover stitch sewing machine which forms double chain stitch seams, needle threads are pulled out from the needle thread tensioning devices, passing over a thread hanging point on a needle thread pulling-up spring and the needle thread take-up completes drawing-up of the needle threads after needle thread loops of the respective needles are seized by the looper. The sewing material is then fed one feed pitch as the needles are moved down and the needle thread take-up draws out the needle threads, while the needle threads are pulled up at the thread hanging point by the elasticity of the needle thread pulling-up spring, thus preventing slack in the needle threads below the needle thread eyes. The threads which are connected with the needle thread loops, are drawn up by the thread hanging point of the needle thread take-up against the resiliency of the needle thread pulling-up spring.