The subject of this graduation project is the main steel arched carrier of the Labin sports centre roof. During the design process, the most important thing was to respect the dimensions of the existing carrier which is made from laminated wood. The span of the main carrier is 24,5 m while the height is 11,38m. The carrier model is a grille whose outer elements are interconnected by slant and vertical profiles, whuch has determined the corresponding profiles of all the elements of which the grille carrier consists of. The profiles of the longitudinal supports of the secondary load-bearing structure have also been determined. The calculation of continuous and variable actions on the support structure was made, and 12 combinations of actions were estimated. The construction was modeled in the computer program STAAD.Pro and after entering all combinations of actions, the most unfavorable ones were determined. The resultant diagrams for the most unfavorable combination of action were obtained and the highest values of the stress resultants were extracted. According to the resultant stresses, it has been proved that the selected profiles of structural elements satisfy the limit state of load capacity and limit state of usability.