Manufacturing method for electrochemical element and electrochemical element

A manufacturing method for an electrochemical element including a metal support, an electrode layer formed on/over the metal support, and an intermediate layer formed on/over the electrode layer, the method comprising:

• an intermediate layer forming step of forming the intermediate layer having a region with a surface roughness (Ra) of 0.224 μm or less on the electrode layer;
• and
• an electrolyte layer forming step of forming an electrolyte layer having a density of 90% or more by spraying aerosolized metal oxide powder onto the intermediate layer,
• wherein the intermediate layer forming step includes smoothing a region of the intermediate layer and heating the intermediate layer at a temperature of 1050° C. or lower,
• wherein the electrode layer is at least partially disposed between the metal support and the electrolyte layer,
• wherein the metal support has at least one through hole inside a region in which the electrolyte layer is formed, and
• wherein the metal support has a thickness of 0.1 mm to 0.5 mm,
• the electrode layer has a thickness of 5 μm to 50 μm,
• the intermediate layer has a thickness of 2 μm to 50 μm,
• the metal support is ferrite-based stainless steel,
• the intermediate layer is GDC or YDC, and
• a metal oxide thin layer is provided on/over a surface of the metal substrate, and
• said metal oxide thin layer is provided also on a surface that is in contact with the electrode layer and an inner surface of the through hole.