A method of manufacturing a device includes forming a conductive film on a second surface of a substrate having a first surface and the second surface opposite to the first surface by using a non-superconducting material, forming a through hole penetrating the substrate by etching the substrate from the first surface after forming the conductive film, forming a through electrode in the through hole by using a superconducting material by an electroplating method using the conductive film exposed in the through hole as a seed layer, and removing the conductive film after forming the through electrode.

A quantum device capable of effectively cooling a quantum chip and an area (e.g., a space) therearound is provided. A quantum device includes a quantum chip and an interposer on which the quantum chip is located. The interposer includes an interposer substrate and an interposer wiring layer. The interposer wiring layer is disposed on a surface of the interposer substrate on a side on which the quantum chip is located. The interposer wiring layer includes, in at least a part thereof, a superconducting material layer formed of a superconducting material and a non-superconducting material layer formed of a non-superconducting material.