To supply an electromagnetic wave shielding member capable of maintaining shielding performance of an electromagnetic wave over a long period to a degree usable as a building material.

A thin plate is formed by using an electromagnetic wave shielding material, and an airtight film is adhered to the obverse side and the reverse side of the thin plate. In that case, the whole thin plate is formed as an airtight structure by covering not only the obverse side and the reverse side but also an end surface of the thin plate with the film. Such constitution can maintain electromagnetic wave shielding performance over a long period since a construction material of the thin plate is not deteriorated when the thin plate is exposed to outside air. Plural thin plates or plural kinds of thin plates may be sandwiched by the airtight film in a combined state, and the mutual thin plates may be joined and sandwiched by welding or an adhesive.