Thanks to the needle-feed mechanism which offers excellent efficiency of feed, the machine ensures accurate stitch pitches (stitch length) as well as preventing slippage of the upper cloth. The bottom feed's locus has been improved to match the needle feed motion, thus the machine produces beautiful seams without stitch gathering, even when it is used for sewing slippery and difficult-to-feed material or for handling a difficult process. The needle feed mechanism is a so-called "dry type", which does not require oiling. With this mechanism, a highly reliable machine structure, free from oil leakage troubles, has been achieved. The frame, which requires only a minute quantity of lubricating oil, is structured to eliminate oil leakage.