PURPOSE: To decrease the stress to be exerted to a conductor pattern and 'Permalloy(R)' pattern and to prevent the deterioration of characteristics by using an ion implantation method at the time of curing a heat resistant thermosetting resin of a memory element so that a treatment at a low temp. is made possible.

CONSTITUTION: The conductor pattern layer 12 is formed via a spacer 11 on a bubble crystal 10 of the magnetic bubble memory element and a heat-resistant thermosetting type silicone resin for forming an interlayer insulating film 13 is coated thereon. The coating is then subjected to low-temp. heating to remove the solvent and thereafter, ions 16 are implanted thereto to cure the resin. A protective film 15 is formed on the insulating film 13 or the 'Permalloy(R)' pattern layer 14. The ion implantation method is used at the time of curing the heat resistant thermosetting resin by which the treatment at the low temp. is made possible, the stress to be exerted to the conductor pattern and 'Permalloy(R)' is decreased and the deterioration of the characteristics is prevented.