PURPOSE: To make large delay time per unit wiring length at a delay line part and to make small the delay time at wiring of a peripheral circuit part by prescribing film thickness of an earth plate at a superconduction transmission line in accordance with a corresponding area.

CONSTITUTION: A signal line 10, a control line 7, etc., of a peripheral circuit, which are linked through a superconduction transmission line 4, earth plates 2 and 11 of the line 4, the line 4 and a Josephson junction 8, are laminated on a substrate 1 together with insulation layers 3, 5 and 9. Film thickness of an area part 2 in correspondence to the line 4 of the earth plate is thinner compared with an area part 11 in correspondence to a peripheral circuit forming part, and an essential magnetic permeability in proportion to the delay time of the part becomes larger. Consequently, the delay time per unit wiring length at a delay line part becomes larger, the delay time at wiring of a peripheral circuit part becomes smaller, and a repeating frequency of the signal can be enhanced and a superconduction delay line memory device with large memory capacity can be obtained.