A printed wiring board includes a laminated structure including insulating layers, and conductive layers laminated on the insulating layer, respectively, such that the conductive layers include an outermost conductive layer having a radiation slot, and an inner-side conductive layer having an excitation portion facing the radiation slot in a lamination direction. The laminated structure has a recess portion recessed from the radiation slot toward the excitation portion such that a bottom surface of the recess portion is positioned between the outermost conductive layer and the excitation portion, and the insulating layers include an insulating layer having at least a portion covering the excitation portion.