Abstract: Modular elements for composing frame for the construction of cabinet structures and containers for electrical, electromechanical and electronic components, for internal and external use, wherein said elements form the perimetral cabinet frame defined by section bars (10, 10') and angle pieces (19, 19', 19") connected together; the angle pieces (19, 19', 19") are constituted by a corner portion (20, 20', 20") from which there extend several mutually orthogonal tube portions (21, 21', 21") of substantially quadrilateral cross-section; the section bars (10, 10') are constituted by tubular elements arranged for insertion onto said tube portions (20, 20', 20") and comprising, extending from one corner (11) thereof in mutually orthogonal directions, two flanges (12) from which there extend two further converging flanges (14) from which there extend two mutually orthogonal profiled portions (16) which can be provided with standardized holes (17) arranged for supporting electronic and electromechanical containers.