Method for manufacturing semiconductor element package, and semiconductor element package

The present invention provides a method for manufacturing a plurality of semiconductor element packages using a substrate sheet having a plurality of semiconductor elements disposed thereon, the manufacturing method being suitable for reducing damage to the semiconductor element packages due to an increase in internal pressure. The provided manufacturing method comprises: obtaining a laminate by bonding a cover sheet and a substrate sheet having a plurality of semiconductor elements disposed thereon to each other with a double-side adhesive sheet therebetween, the double-side adhesive sheet having a plurality of through-holes and comprising a porous body sheet and an adhesive layer pre-formed on each of both surfaces of the porous body sheet, with the semiconductor elements positioned in the through-holes and covered by the cover sheet; and dividing the laminate so that a plurality of covers, a plurality of substrates, and a plurality of porous bodies are obtained respectively from the cover sheet, the substr