A memory device includes a memory module and a control module. The control module is coupled to the memory module and is configured to store data into the memory module according to a first mapping table. The control module includes a storing unit and a guaranteeing unit. The storing unit is configured to store the first mapping table. The guaranteeing unit is coupled to the storing unit and is configured to determine whether the first mapping table is correct or not. The guaranteeing unit is further configured to issue an error signal in a state where the first mapping table is incorrect.