Leakage of electromagnetic noise from a wiring substrate is suppressed. A wiring substrate (1) includes a multilayered wiring layer, a structure (8) of a conductor, and an electromagnetic wave absorber (5). An electronic component (2) which is an example of an electromagnetic noise generation source is mounted on the wiring substrate (1). The electronic component (2) has a high-frequency circuit. The structure (8) is formed using the multilayered wiring layer, and is arranged so as to enclose the electronic component (2) in plan view with an opening (4) in the enclosure. The electromagnetic wave absorber (5) is arranged so as to cover the opening (4).