PURPOSE: To easily connect floor posts of different types.

CONSTITUTION: In a floor posts 10, a floor supporting fixture 7 in the shape of a square without a side in which a lower piece 3 is longer than an upper piece 1, and floor mounting holes 4, 5 and 6 are provided respectively at the upper piece 1, an intermediate piece 2 and the lower piece 3, is provided at the upper end of a support 8, and a base 9 is provided at the lower end of the support 8. A floor support part 20 in the shape of the letter L is made removably mountable on each of the floor mounting holes 4, 5 and 5. Thus, a small-sized floor panel 40 and a large-sized floor panel 50 of the different type can be easily connected to each other without increasing the number of parts or complicating the structure.