A wiring board on which electronic components are mountable includes a stretchable portion having stretchability and having a first surface and a second surface opposite to the first surface, and an interconnection wire electrically connected to the electronic components mounted on the wiring board. The stretchable portion includes first regions lined up in each of a first direction and a second direction, a second region including first portions and second portions, and a third region surrounded by the second region. The first regions overlap the electronic components. The first portion extends from one of two first regions neighboring each other in the first direction to the other thereof. The second portion extends from one of two first regions neighboring each other in the second direction to the other thereof. The second region has a lower modulus of elasticity than the first region. The interconnection wire overlaps the second region.