A wiring board module includes a multilayer wiring board. A crystal oscillator and an IC component, for example, are mounted on the mounting surface of the multilayer wiring board. Mounting lands for the IC component, mounting lands for the crystal oscillator, and mounting lands for other surface mount components are provided on the mounting surface. Each mounting land for the crystal oscillator is not a conventional single large-area land but is defined by four adjacent land pieces. The four land pieces are electrically connected via an external terminal of the crystal oscillator, thereby functioning as a mounting land for the external terminal. In other words, each of the plurality of mounting lands provided at locations corresponding to external terminals of the crystal oscillator is divided into four land pieces.