PURPOSE: To simply attach a column fixing member and a connecting member to a column without damaging the end of the column by severally attaching and detaching them to the ends of adjacent columns, and stretchingly adjusting the length of the beam.

CONSTITUTION: The band 33 and a holder 36 of a column fixing member 31 are attached to a column on both its sides, and mutually connected with bolts 35. A pressing jack bolt 41 is rotated to pressedly hold the column between a pressing plate 43 and a band 33. In addition, a connecting member 32 is connected to each column fixing member 31. The pipe 45 of the connecting member 32 is then rotated to set up the length of a temporary beam 30 to a proper space. Thus the column fixing member and the connecting member can be simply attached to the column without damaging the end of the column, and can well correspond to various spaces between columns.