A magnetic bubble memory device comprises a cassette and a body. The cassette has a bias magnetic field generator adapted to generate a bias magnetic field for sustaining magnetic bubbles within a bubble memory chip and is removed of coils adapted to generate a rotating magnetic field for propagation of the magnetic bubbles. The body has a rotating magnetic field generator. The cassette is mounted to or dismounted from the body. When the cassette is dismounted from the cassette, information stored in the chip is held by the bias magnetic field generator and when the cassette is mounted to the body, information is read from or written into the chip by the rotating magnetic field generator.