Provided is a storage device including a power management integrated circuit chip; multiple non-volatile memories configured to receive power from the power management integrated circuit chip; and a controller configured to control the non-volatile memories, wherein the controller checks a state of the power during a read operation and a write operation on the non-volatile memories and, when a power failure is detected in at least one of the non-volatile memories, implements a power failure detection mode regarding the read operation and the write operation on all of the non-volatile memories.