A circular knitting machine for knitwear (1 ), of an "open" type and configured for producing fabric (T) and collecting it in an open configuration, i.e. in a single layer, comprising a base frame (2) constituting the bearing structure of the machine and provided with a support upper ring or element (3), with a lower base or cross-base (4), and with at least two support legs (5, 6) interposed between, and connecting, in at least two distinct and laterally distanced positions, the upper ring and the lower base, such that the upper ring (3) is vertically superposed on, and distanced from, the lower base (4), and in that between them a collecting space (S) is vertically defined. The machine comprises a knitting head (H) mounted to the upper ring (3) and provided with at least a rotating needle-bearing organ (0), being in a form of a needle cylinder or a needle plate, with a plurality of needles movably mounted to the needle-bearing organ, and with command means for selectively activating the plurality of needles for enabling production of a fabric. The machine comprises a take-down and/or collecting group (30) movably housed in the collecting space (S) and able to open and stretch the fabric produced by the machine, winding it in a single layer and continuously on at least a collecting roller (31). The whole take-down and/or collecting group is rotatably mounted hanging to the base frame (2) or to the needle-bearing organ (0), such as to be vertically suspended in the collecting space (S).