A developer storage container comprising: a container wall ; a substrate member having a first surface and a second surface opposite to each other; and a storage portion provided on the container wall and storing the substrate member , wherein the storage portion comprises: an outer surrounding wall provided on the container wall ; a first support portion disposed inside the outer surrounding wall , the first support portion supporting the first surface of the substrate member ; a second support portion disposed inside the outer surrounding wall and connected to the container wall , the second support portion supporting the first surface of the substrate member ; and a lid portion fixed to the outer surrounding wall and having an opening through which the substrate member is exposed, the lid portion contacting the second surface of the substrate member , wherein the lid portion includes a first protrusion and a second protrusion protruding in a second direction perpendicular to a first direction from the substrate member to the container wall ; wherein a distance (d2, d4) between the first protrusion and the second protrusion in the second direction is shorter than a length (d3) of the substrate member in the second direction; wherein the outer surrounding wall has a through-hole disposed so as to face the second support portion , and wherein the through-hole is exposed to outside so as to allow a tool to access the second support portion through the through-hole . a container wall ; a substrate member having a first surface and a second surface opposite to each other; and a storage portion provided on the container wall and storing the substrate member , wherein the storage portion comprises: an outer surrounding wall provided on the container wall ; a first support portion disposed inside the outer surrounding wall , the first support portion supporting the first surface of the substrate member ; a second support portion disposed inside the outer surrounding wall and connected to the container wall , the second support portion supporting the first surface of the substrate member ; and a lid portion fixed to the outer surrounding wall and having an opening through which the substrate member is exposed, the lid portion contacting the second surface of the substrate member , an outer surrounding wall provided on the container wall ; a first support portion disposed inside the outer surrounding wall , the first support portion supporting the first surface of the substrate member ; a second support portion disposed inside the outer surrounding wall and connected to the container wall , the second support portion supporting the first surface of the substrate member ; and a lid portion fixed to the outer surrounding wall and having an opening through which the substrate member is exposed, the lid portion contacting the second surface of the substrate member , wherein the lid portion includes a first protrusion and a second protrusion protruding in a second direction perpendicular to a first direction from the substrate member to the container wall ; wherein a distance (d2, d4) between the first protrusion and the second protrusion in the second direction is shorter than a length (d3) of the substrate member in the second direction; wherein the outer surrounding wall has a through-hole disposed so as to face the second support portion , and wherein the through-hole is exposed to outside so as to allow a tool to access the second support portion through the through-hole . <EOS>