PURPOSE: To facilitate an easy address control for the magnetic bubble element using the major-minor loop system by preparing the index minor loop containing the address information and the flag with every minor loop.

CONSTITUTION: The index information comprising the flag and the minor address information is held within the magnetic bubble element. Based on this information, the initial setting is carried out at the remaking time after break of the power supply. When the information is read out of the index minor loop, whether or not the information is the flag is examined first. If the information is the flag, the subsequent information are regarded as the minor loop addresses. And the contents of the addresses are supplied to the minor address counter to perform the initial setting. In case a number of magnetic bubble elements have operations at one time, the index minor loop information is written previously into the nondefective minor loop in order to enhance the reliability.