To provide an air-processed yarn and an air-processed false-twist yarn, each capable of exhibiting unconventionally high stretchability while having high bulkiness and soft touch feeling, to provide a production unit for such yarns, and to provide woven fabrics and knitted fabrics using such yarns.

This air-processed yarn is obtained by combining treatment with air of 1st core yarns 11a consisting of filament yarns, a 2nd core yarn 11b consisting of a polyurethane monofilament yarn and floating yarn 12. In making the combining treatment, the 2nd core yarn 11b is extended, and in the natural condition under no tension, returns to the original state, therefore the whole filament yarn is contracted in the length direction, and as the 2nd core yarn 11b is extended by tension or the like, the filament yarn is extended as a whole.