A stretchable mounting board that includes: a stretchable substrate; a mounting electrode portion on a main surface side of the stretchable substrate and containing a conductive filler and a resin; a solder portion connected to the mounting electrode portion; and an electronic component electrically connected to the mounting electrode portion with the solder portion interposed therebetween. The mounting electrode portion has a first main surface on a stretchable substrate side thereof, a second main surface on a solder portion side thereof, a first region including the first main surface, and a second region including the second main surface, and wherein, in a cross-section along a thickness direction of the mounting electrode portion passing through the first region and the second region, a sectional area of the conductive filler in the second region is larger than a sectional area of the conductive filler in the first region.