To provide a building structure and its frame structure in consideration of an overall building so as to actuate various facilities of plumbing, etc., to support a whole say operating state without influencing upon operation and to freely perform maintenance and inspection without stopping operation.

A building structure 1 constitutes facility spaces 10, 10' constructed of truss frames 31-, 41- arranging an operation supporting facility on upper parts of operating floors 3, 4, makes a piping space of plumbing, etc., of an underfloor pit 2 excluding a foundation by directly connecting a pile 6 and a column 5 supporting the operating floors 3, 4 and the facility spaces 10, 10' to each other and arranges inspection footpaths 15, 15' in the facility space.