According to one embodiment, storage device, a CRC generator device and a CRC generation method includes A storage device includes: a storage unit 1, a data reading unit 2, and a CRC generation device 3. The CRC generation device 3 includes a CRC generation unit 31 generates a first CRC value; an ECC unit 32 detects an error sequence in a reverse order; a CRC reverse operation unit 33 calculates a CRC reverse operation result for the error sequence; a CRC generation shift register group 34 to retain CRC conversion information; an error sequence CRC generation unit 35 obtains a second CRC value; and an XOR unit 36 obtains a CRC value for an errorless recording sequence.