PURPOSE: To promote execution efficiency by providing an opening constituted of an upper wing plate provided near to a pedestal of one column and a lower wing plate provided near to a column's head of the other column and fitting the columns to the central part thereof.

CONSTITUTION: A column and beam connecting wing plate 10 constituted of an upper wing plate 11 and a lower wing plate 12 is formed, and the upper and lower wing plates 11 and 12 have a square opening to which columns' bodies 21 are fitted. After that, the lower wing plate 12 is provided near to columns' heads of two columns 20 to build beams 30, and they are connected with bolts. Then, the lower end 24 of the column fixing the upper wing plate 11 near to a pedestal thereof is inserted into a part of the end 31 of four beams 30, and they are connected with bolts. According to the constitution, the beams 30 can be surely connected to the columns 20.