PURPOSE: To reduce cost by constructing the foundation of a heavy device with a pier structure carried on an integral base rigidly clamping the foundation, and forming a bridge girder type foundation structure having the rigid foundation as a pier.

CONSTITUTION: A foundation for rolls 1a, 1b and the like is excavated deep from a ground surface 6, and piers 4 are piled to an extent corresponding to the weight thereof and ground hardness. In addition, piled space is filled with concrete 5 and anchor bolts 3 are jointed to bases 10. Also, a table roller carried on the integrated base of pier structure is placed between the bases 10 and 10. According to the aforesaid construction, the foundation needs not be excavated over the whole length of a facility, and cost can be reduced.