A steering column device where an inner column can be reliably clamped and sufficient rigidity and strength of an outer column can be achieved. A semi-circular arc rib (132) is formed on the peripheral edge of a closed end section (131) of a slit (13). The rib (132) is substantially semi-circular are-shaped and projects outward from an outer peripheral surface (15A) of an outer column (1). Further, linear ribs (133A, 133B) extend linearly toward the vehicle body front side so as to be continuous from the vehicle body front side of the semi-circular arc rib (132). The semi-circular arc rib (132) and the linear ribs (133A, 133B) reinforce the peripheral edge of the slit (13) of the outer column (1) whose rigidity and strength are impaired. Thus the rigidity and strength of the outer column (1) are improved.