are same as in the double chainstitch sewing machine in the first embodiment the needle thread take up mechanism differs from the needle thread take up mechanism in the first embodiment in the following points as shown in fig4 and fig5 a thread take up cam 55 is supported by a needle bar 1 that is a mounting part 55 a of the thread take up cam 55 is affixed to a bracket 57 fixed to a needle holder 3 by a screw 58 so as to be adjustable in lateral position and the thread take up cam 55 is supported by the needle bar 1 and it moves up and down together with the needle bar 1 unlike the first embodiment a fixed thread guide 52 is composed of a pair of right and left plates and a pin 61 for fitting a holder 63 is provided at its upper end the fixed thread guide 52 is disposed at the right and left side of the thread take up cam 55 the holder 63 is affixed to the outside of a jaw 43 a of a sewing machine arm 43 by a screw 62 so as to be adjustable in vertical position a pin 61 projecting to a side is supported by the holder 63 so as to be slidable laterally and rotatable and is fixed to the holder 63 by a screw 64 the fixed thread guide 52 has mutually confronting right and left thread eyes the thread take up cam 55 is engaged with needle threads 51 a 51 b 51 c passed in the fixed thread guides 52 at both.