A column structure (10) is configured in such a manner that a base member (16) is affixed on a foundation (12) with mortar (14) therebetween, the mortar (14) serving as an affixation member. First and second anchor bolts (24) serving as anchor members are used to affix the base member (16). An iron column (30) serving as a column member is joined to the upper side of the base member (16), the iron column (30) having flanges (30B) formed integrally therewith at opposite ends of the web (30A) in the width direction. A shear resistance member (30C) embedded within at least the mortar (14) is provided at the lower part of the web (30A). The shear resistance member (30C) improves the shear strength of the column member (10).
