A liquid discharge structure comprising: a casing having a plate-shaped bottom wall with a discharge opening for liquid, the liquid being collected inside the casing which is configured to be installed in a vehicle; a blocking wall outside the bottom wall of the casing, wherein the blocking wall is overlapped with the discharge opening in a plan view on the bottom wall and opposed to the bottom wall with a gap between the blocking wall and the bottom wall; and a fixing mechanism which is disposed not to be overlapped with the discharge opening in the plan view, wherein the fixing mechanism is configured to fix the blocking wall relative to the bottom wall in an attachable and detachable manner, wherein the fixing mechanism comprises: an engaged hole in the bottom wall; and an engaging section arranged vertically on the blocking wall so that in the first state, a tip portion of the engaging section enters the engaged hole in the bottom wall, wherein an engaging claw projects from the tip portion, the engaging claw being configured to be engaged with and locked to an edge of the engaged hole, characterized in that the fixing mechanism comprises: a hinge section configured to couple the blocking wall to the bottom wall so as to allow the blocking wall to be rotated between a first state and a second state, wherein in the first state, the blocking wall is opposed to the bottom wall, and in the second state, the blocking wall is separated away from the bottom wall around a predetermined rotation axis. a casing having a plate-shaped bottom wall with a discharge opening for liquid, the liquid being collected inside the casing which is configured to be installed in a vehicle; a blocking wall outside the bottom wall of the casing, wherein the blocking wall is overlapped with the discharge opening in a plan view on the bottom wall and opposed to the bottom wall with a gap between the blocking wall and the bottom wall; and a fixing mechanism which is disposed not to be overlapped with the discharge opening in the plan view, wherein the fixing mechanism is configured to fix the blocking wall relative to the bottom wall in an attachable and detachable manner, wherein the fixing mechanism comprises: an engaged hole in the bottom wall; and an engaging section arranged vertically on the blocking wall so that in the first state, a tip portion of the engaging section enters the engaged hole in the bottom wall, wherein an engaging claw projects from the tip portion, the engaging claw being configured to be engaged with and locked to an edge of the engaged hole, characterized in that the fixing mechanism comprises: a hinge section configured to couple the blocking wall to the bottom wall so as to allow the blocking wall to be rotated between a first state and a second state, wherein in the first state, the blocking wall is opposed to the bottom wall, and in the second state, the blocking wall is separated away from the bottom wall around a predetermined rotation axis. an engaged hole in the bottom wall; and an engaging section arranged vertically on the blocking wall so that in the first state, a tip portion of the engaging section enters the engaged hole in the bottom wall, wherein an engaging claw projects from the tip portion, the engaging claw being configured to be engaged with and locked to an edge of the engaged hole, characterized in that the fixing mechanism comprises: a hinge section configured to couple the blocking wall to the bottom wall so as to allow the blocking wall to be rotated between a first state and a second state, wherein in the first state, the blocking wall is opposed to the bottom wall, and in the second state, the blocking wall is separated away from the bottom wall around a predetermined rotation axis.