A wiring board that includes: a wiring conductor; a first dielectric layer around the wiring conductor and containing a first glass and a first ceramic filler; and a second dielectric layer interposed between the wiring conductor and the first dielectric layer, the second dielectric layer being in contact with the wiring conductor and the first dielectric layer, and the second dielectric layer containing a second glass and a second ceramic filler. A sintering temperature of the second glass contained in the second dielectric layer is higher than a sintering temperature of the wiring conductor, and a grain size of the second glass contained in the second dielectric layer is smaller than a grain size of the first glass contained in the first dielectric layer.