A wiring board (10) of the present invention includes: a through hole (11b), provided in a semiconductor chip mounted region (15), penetrating the wiring board (10); and a groove pattern (13), provided on a solder resist (9) formed on the semiconductor chip mounted region (15), leading to the through hole (11b). The foregoing configuration makes it possible to guide, via the groove pattern (13) to the through hole (11b), moisture that collects in the semiconductor chip mounted region (15) and therefore to effectively discharge the moisture from the semiconductor chip mounted region (15). Thus, a semiconductor device (30) that employs the wiring board (10) does not suffer from vaporization and expansion, inside of it, due to heat that is applied at the time of manufacturing the semiconductor device (30) and at the time of mounting the semiconductor device (30) on a mount substrate. It is therefore possible to reduce expansion of the semiconductor device.