withdrawn from the water 7 before introduction to the interlacing nozzle 8 the two yarns y and ya are entangled to each other while passing through the interlacing nozzle 8 according to the addition of the carrier yarn ya the mechanical properties of the resultant yarn can be improved to a great extent and stable operations are achievable in this yarn texturing process as well as in the post treatment of the yarn such as rewinding or weaving the present invention is applicable not only on a raw filament yarn as stated above but also on a textured yarn produced for example by a false twist texturing machine and a draw texturing machine in this connection such a conventional texturing machine can be combined upstream of the apparatus according to the present invention in a continuous manner effects of the present invention will be apparent from the following example various samples of the fancy yarn were obtained from a starting yarn of polyester filament 2 u00d7 50 d 36 f in a doubled state by run nos 1 to 6 each being carried out by means of the apparatus illustrated in fig2 and 4 to 8 respectively the yarn configurations of the samples were.