A substrate includes: a wiring substrate; a lower plate disposed below the wiring substrate; a canted coil spring disposed between the lower plate and the wiring substrate; an electronic component package disposed above the wiring substrate; a sheet disposed between the wiring substrate and the electronic component package and including a plurality of connection members that connects a plurality of first electrodes provided on an upper surface of the wiring substrate and a plurality of second electrodes provided on a lower surface of the electronic component package; an upper plate disposed on the electronic component package; and a coupling member that couples the lower plate and the upper plate, wherein the lower plate, the canted coil spring, the wiring substrate, the sheet, the electronic component package, and the upper plate are laminated and fixed in this order by coupling the lower plate and the upper plate by the coupling member.