Abstract: Platform units for scaffolding must be light and strong in design and be usable without risk of accident. Therefore, all their parts are designed for a long service life, and should also be included in the static analysis. High rigidity of the corner joints of the rectangular support frame for the platform unit is thereby advantageous as well as having the narrowest possible gaps between adjacent platform units. The invention uses for this purpose, a three-dimensional arrangement of the mounting brackets on the support frames, which combine relative structural symmetry with the fact that the mounting brackets are offset, and thus permit a narrow gap formation between the platform units. The corner joints of the support frames are, in spite of their light construction, resistant to distortion and any uncertainty due to the use of wooden planks for the floor surface is avoided by using a friendly holding frame.