A dynamic semiconductor memory device provides a selected real cell, which is connected to a first of a pair of bit lines connected to a sense amplifier, and a dummy cell which is connected to a second of the pair of bit lines so as to perform a read-out operation. The dynamic semiconductor memory cell further provides an active restore circuit for pulling up the bit line potential of the bit line on the higher potential side of the pair of bit lines, in which the potential difference is increased by the read-out operation. The dynamic semiconductor cell can also provide a write-in circuit for charging the selected real cell through the bit line. A test power source pad is provided in the active restore circuit or the write in circuit so that when the reference level of the real cell is tested an optional power source can be applied from the test power source pad instead of from a normal power source.