PURPOSE: To avoid impact sounds associated with vertical action of a needle rod drive member by holding the needle rod drive member of a pause sewing head at a drive releasing position where the transmission of a driving force is cut off to a needle rod over the entire area of a vertical stroke.

CONSTITUTION: This apparatus is provided with a cam face 28 formed flatly with respect to the vertical way of a needle rod drive member 24 and a drive releasing mechanism 40 which allows operation of rolling the needle drive member 24 being engaged with the cam face 28 to a drive releasing position where the transmission of driving is cut off to a needle rod 30 while being made ready to lock under this operating condition. The vertical length of the cam face 28 is so set to such dimensions that the engagement with the drive releasing mechanism 40 is held over the entire area of a vertical stroke of the needle drive member 24.