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 (30, 30a) provided on the container wall and storing the substrate member, wherein the storage portion (30, 30a) 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 (32, 32e) fixed to the outer surrounding wall and having an opening through which the substrate member is exposed, the lid portion (32, 32e) contacting the second surface of the substrate member, wherein the lid portion (32, 32e) includes a first protrusion (321, 322, 321e, 322e) and a second protrusion (323, 324, 323e, 324e) 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 (321, 322, 321e, 322e) and the second protrusion (323, 324, 323e, 324e) in the second direction is shorter than a length 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 (30, 30a) provided on the container wall and storing the substrate member, wherein the storage portion (30, 30a) 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 (32, 32e) fixed to the outer surrounding wall and having an opening through which the substrate member is exposed, the lid portion (32, 32e) 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 (32, 32e) fixed to the outer surrounding wall and having an opening through which the substrate member is exposed, the lid portion (32, 32e) contacting the second surface of the substrate member, wherein the lid portion (32, 32e) includes a first protrusion (321, 322, 321e, 322e) and a second protrusion (323, 324, 323e, 324e) 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 (321, 322, 321e, 322e) and the second protrusion (323, 324, 323e, 324e) in the second direction is shorter than a length 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.