To provide a method for producing a processed yarn having a non- twisted structure, excellent in high elasticity and covering property and also in post-processing property, and to obtain a highly elastic processed yarn having the non-twisted structure, having a stiffness and puffy feeling, capable of exhibiting an expressive feeling on preparing a knitted or woven fabric, and suitable for the knitted or woven fabric used as a clothe.

This highly elastic false-twisted processed yarn is constituted of a polyurethane elastic yarn and plural thermoplastic multifilament yarns and has a structure in which the polyurethane elastic yarn positions at the central part or in the vicinity of the central part, the thermoplastic multifilament yarns surrounds it and the polyurethane elastic fiber is covered by the thermoplastic multifilament yarns so as not to expose the polyurethane yarn essentially to the outside part of the thermoplastic multifilament yarns when viewing at any optional cross sectional surface of the yarn, and all the yarns are interlaced.