An electronic device having a shield structure is disclosed. The shield structure includes a conductive heat diffusion plate that is provided in a position facing a mounting surface of an electronic circuit board on which electronic components, such as a CPU, are mounted, and diffuses heat generated from the CPU, etc.; and a conductive sponge-like member that is firmly fixed to at least either the mounting surface of the electronic circuit board or a surface of the conductive heat diffusion plate which faces the mounting surface of the electronic circuit board, and is provided to separate the CPU, etc. which generate electromagnetic wave noise from antennas.