A guiding and calibration device (100) of a blown plastic film is described, comprising a bearing structure (1, 2) which includes equidistant rotation fulcrums (3) of rotating structures (4) along an ideal circumference. Each rotating structure (4) comprises a rotating vertical upright (43) and at least one arm (44, 45) fixed to said rotating vertical upright (43). A vertical floating element (5) is rotatably fixed to the at least one arm (44, 45). The device (100) further comprises groups of rectilinear bars (12a, 12b) consisting of at least one pair of rectilinear bars (12a, 12b) parallel to each other and placed slidingly side by side along respective external edges.