To provide a foundation base for equipment devices which sufficiently secures the positioning accuracy of anchor bolts for installation of equipment devices and improves the workability at the time of construction of the foundation base and also provides a sufficient strength against the vibration of the equipment devices installed there.

After the fitting position of equipment devices on the upper face of a steel skeleton frame 3 has been precisely measured, pierced holes 7a, 7b piercing the upper and lower flange members 2a, 2b of the steel skeleton member 2 at the position are formed. A sleeve 8 is inserted in the upper pierced hole 7a to get in contact with the lower flange member 2b and connected thereto and an anchor bolt 9 for installation of equipment devices is inserted in the arranged sleeve 8 and the height is accurately adjusted. Then, the upper and lower ends of the sleeve 8 are fixed by nuts 10 to secure the position of the anchor bolt 9.