A circular knitting machine for knitwear, of an "open" type and configured for producing fabric and collecting it in an open configuration, i.e. in a single layer, the machine comprising: - a base frame constituting the bearing structure of the machine; - a knitting head mounted to said base frame and provided with at least a needle-bearing organ, being in a form of a needle cylinder or a needle plate, with a plurality of needles movably mounted to said at least a needle-bearing organ, and with command means for selectively activating said plurality of needles for enabling production of a fabric; wherein said base frame comprises: - a support upper ring or element, on which said knitting head is mounted such that said needle-bearing organ can rotate about a substantially-vertical central axis; - a lower base, or cross-base, destined to be at least partially rested on the ground; wherein between said upper ring and said lower base a collecting space is vertically defined, free of elements of said base frame and destined to movably house a take-down and/or collecting group of said fabric produced by the knitting machine; the knitting machine being characterized in that it comprises two and only two support legs (5, 6) interposed between, and connecting, in two distinct and laterally distanced positions, said upper ring and said lower base, such that said upper ring is vertically superposed on, and distanced from, said lower base, said two legs (5, 6) being arranged in correspondence of two respective sides of said upper ring and of said lower base, or cross-base, in such a way as to laterally delimit said collecting space. - a base frame constituting the bearing structure of the machine; - a knitting head mounted to said base frame and provided with at least a needle-bearing organ, being in a form of a needle cylinder or a needle plate, with a plurality of needles movably mounted to said at least a needle-bearing organ, and with command means for selectively activating said plurality of needles for enabling production of a fabric; wherein said base frame comprises: - a support upper ring or element, on which said knitting head is mounted such that said needle-bearing organ can rotate about a substantially-vertical central axis; - a lower base, or cross-base, destined to be at least partially rested on the ground; wherein between said upper ring and said lower base a collecting space is vertically defined, free of elements of said base frame and destined to movably house a take-down and/or collecting group of said fabric produced by the knitting machine; the knitting machine being characterized in that it comprises two and only two support legs (5, 6) interposed between, and connecting, in two distinct and laterally distanced positions, said upper ring and said lower base, such that said upper ring is vertically superposed on, and distanced from, said lower base, said two legs (5, 6) being arranged in correspondence of two respective sides of said upper ring and of said lower base, or cross-base, in such a way as to laterally delimit said collecting space. - a support upper ring or element, on which said knitting head is mounted such that said needle-bearing organ can rotate about a substantially-vertical central axis; - a lower base, or cross-base, destined to be at least partially rested on the ground;