Radio wave absorber and method for forming radio wave absorber

A radio wave absorber comprising:

• a first layer and a second layer that are stacked one another and respectively having dielectric constants that are different from each other, wherein
• the dielectric constants of the first layer and the second layer are set such that a first reflected wave and a second reflected wave have a same intensity,
• a thickness of the first layer is set such that the first reflected wave and the second reflected wave have a phase difference so that the first reflected wave and the second reflected wave at least partially cancel each other,
• the first reflected wave is a reflected wave that is reflected on an exposed surface of the first layer when a target radio wave at a specified frequency is incident on the exposed surface of the first layer,
• the second reflected wave is a reflected wave that is incident from the exposed surface of the first layer, reflected on a boundary surface between the first layer and the second layer, and emitted from the exposed surface of the first layer, and
• the exposed surface of the first layer is a surface of the first layer on an opposite side of the boundary surface.