The present invention provides an electronic component sealing lid which contains a liquid crystal polymer and suppresses detachment caused by reflow treatment. The electronic component sealing lid (10) according to the present invention includes a substrate that is formed from a liquid crystal polymer and includes a base section (11) and a wall section (12), and an inorganic substance (30) contained in the wall section (12), wherein the exposed area percentage for the inorganic substance (30) at a bonding surface (10a) of the wall section (12) is at least 5%.