A screw assembly is made up of a screw and a screw fixing member. The screw fixing member is inserted into a starting hole formed in a concrete wall and then the screw is driven into the fixing member in a continuous manner. The screw fixing member has a body having a cylindrical section formed with an eccentric bore having an opening at one end thereof. The screw has its tip inserted in the opening of the bore. The screw has a threaded shank and a cylindrical portion provided at one end of the shank. The screw and the screw fixing member are coupled together by inserting the cylindrical portion of the screw into the opening of the bore.