Substrate layered body producing method and substrate layered body

A method of producing a substrate layered body, comprising:

• preparing:
• a first layered body in which a first resin layer, a first substrate, and a first inorganic material layer are layered in this order, the first resin layer is disposed at one surface, and the first inorganic material layer is disposed at another surface;
• and a second layered body in which a second resin layer, a second substrate, and a second inorganic material layer are layered in this order, the second resin layer is disposed at one surface, and the second inorganic material layer is disposed at another surface;
• bringing the first resin layer of the first layered body and the second inorganic material layer of the second layered body into contact with each other, thereby layering the first layered body and the second layered body;
• and
• heating the first layered body and the second layered body at 100° C. or more after the layering of the first layered body and the second layered body.