PURPOSE: To erase only the information that is written erroneously to a defective minor loop, by providing a conductor pattern which is orthogonal to the minor loop group to a conductor layer.

CONSTITUTION: The conductor patterns 19, 20, 23, etc. formed with a main pattern 21, a branch pattern 22, etc. and orthogonal to the minor loop groups 5, 5'... are provided to the conductor layer. Then the pattern 21 corresponding to the defective minor loops 5, 5'... is cut off, and a current is applied to the loop 21. Thus the magnetic bubble of a corresponding part 24 is erased by a current magnetic field which is generated via the part 24 of the loop 22 corresponding to the cut-off part 25. As a result, it is possible to erase in terms of hardware also the only undesired magnetic bubble information that is written erroneously to the defective minor loop. This improves the reliability of a magnetic bubble memory device.