A semiconductor memory device includes: a bank including a normal area including normal columns, and a redundancy area including redundancy columns and to be replaced with a failure column of the normal area; sense amplifiers connected to the normal area; and a redundancy sense amplifier connected to the redundancy area. A normal replacement unit is formed of normal columns allocated to each of the sense amplifiers. A redundancy replacement unit is formed of redundancy columns allocated to the redundancy sense amplifier. The redundancy replacement unit is smaller than the normal replacement unit.