An illumination device comprising: an organic EL panel; and a mounting member (170, 252, 281, 403) configured to attach the organic EL panel to a wall surface (300, 600, 600a, 600b), the organic EL panel being attachable to and detachable from the mounting member (170, 252, 281, 403), wherein the organic EL panel comprises: a panel body having an emission surface on its front face side and a circuit board on its rear face side; and a fixing member having a rear face side cover, the rear face side cover including a main body (72, 530) and a raised part, wherein the raised part is disposed on a rear face side of the organic EL panel and raised from the main body (72, 530) to circumvent the circuit board and to protect a part or whole of the circuit board, wherein the raised part includes at least two raised-side engagement parts protruding in a direction crossing a raised direction of the raised part, the two raised-side engagement parts protruding in a direction away from each other, wherein the mounting member (170, 252, 281, 403) includes: an attachment side main body (180, 253, 282, 520); and at least two attachment side engagement parts (182, 255, 521, 522) extending from the attachment side main body (180, 253, 282, 520) to form a step with respect to the attachment side main body (180, 253, 282, 520), the two attachment side engagement parts (182, 255, 521, 522) extending in a direction approaching each other, characterized in that a central part of the rear face side cover including the raised part protrudes toward the rear face side in a side view, and in that when the organic EL panel is attached to the mounting member (170, 252, 281, 403), the organic EL panel is slid relatively to the mounting member (170, 252, 281, 403) in a spreading direction of the emission surface, with the raised part between the two attachment side engagement parts (182, 255, 521, 522), to engage the two raised-side engagement parts with the two attachment side engagement parts (182, 255, 521, 522). an organic EL panel; and a mounting member (170, 252, 281, 403) configured to attach the organic EL panel to a wall surface (300, 600, 600a, 600b), the organic EL panel being attachable to and detachable from the mounting member (170, 252, 281, 403), wherein the organic EL panel comprises: a panel body having an emission surface on its front face side and a circuit board on its rear face side; and a fixing member having a rear face side cover, the rear face side cover including a main body (72, 530) and a raised part, wherein the raised part is disposed on a rear face side of the organic EL panel and raised from the main body (72, 530) to circumvent the circuit board and to protect a part or whole of the circuit board, wherein the raised part includes at least two raised-side engagement parts protruding in a direction crossing a raised direction of the raised part, the two raised-side engagement parts protruding in a direction away from each other, a panel body having an emission surface on its front face side and a circuit board on its rear face side; and a fixing member having a rear face side cover, the rear face side cover including a main body (72, 530) and a raised part, wherein the raised part is disposed on a rear face side of the organic EL panel and raised from the main body (72, 530) to circumvent the circuit board and to protect a part or whole of the circuit board, wherein the raised part includes at least two raised-side engagement parts protruding in a direction crossing a raised direction of the raised part, the two raised-side engagement parts protruding in a direction away from each other, wherein the mounting member (170, 252, 281, 403) includes: an attachment side main body (180, 253, 282, 520); and at least two attachment side engagement parts (182, 255, 521, 522) extending from the attachment side main body (180, 253, 282, 520) to form a step with respect to the attachment side main body (180, 253, 282, 520), the two attachment side engagement parts (182, 255, 521, 522) extending in a direction approaching each other, characterized in that a central part of the rear face side cover including the raised part protrudes toward the rear face side in a side view, and in that when the organic EL panel is attached to the mounting member (170, 252, 281, 403), the organic EL panel is slid relatively to the mounting member (170, 252, 281, 403) in a spreading direction of the emission surface, with the raised part between the two attachment side engagement parts (182, 255, 521, 522), to engage the two raised-side engagement parts with the two attachment side engagement parts (182, 255, 521, 522). an attachment side main body (180, 253, 282, 520); and at least two attachment side engagement parts (182, 255, 521, 522) extending from the attachment side main body (180, 253, 282, 520) to form a step with respect to the attachment side main body (180, 253, 282, 520), the two attachment side engagement parts (182, 255, 521, 522) extending in a direction approaching each other, characterized in that a central part of the rear face side cover including the raised part protrudes toward the rear face side in a side view, and in that when the organic EL panel is attached to the mounting member (170, 252, 281, 403), the organic EL panel is slid relatively to the mounting member (170, 252, 281, 403) in a spreading direction of the emission surface, with the raised part between the two attachment side engagement parts (182, 255, 521, 522), to engage the two raised-side engagement parts with the two attachment side engagement parts (182, 255, 521, 522).