【課題】 二重蓋の点検口構造において、外蓋の意匠性 を保ちつつ、内蓋、外蓋の係脱手段とを一体成形してコ ストダウンを図るとともに全体厚を減少させる。
【解決手段】 壁面３の点検口100 をその前方から着脱 可能に被蓋する内蓋２の両端面外側と、内蓋１よりも一 回り大きな薄箱状の外蓋２の両端面12内側との間に内蓋 １に対して外蓋２を係脱する係脱手段５を設けて、内蓋 １に対して外蓋２を両端面部分の係合関係で係脱可能に 支持して、全厚ｔを薄くする。
PROBLEM TO BE SOLVED: To provide an inspection hole structure for a double cover which is integrally incorporated with a releasing means for an inner cover and an outer cover so as to reduce the cost while an artistic design of the outer cover being kept, and to reduce the overall thickness thereof. SOLUTION: A releasing means 5 for releasing a thin outer cover 2 from an inner cover 1 for covering an inspection hole 100 formed in a wall surface 3 in front thereof, are provided between the outside of the opposite end surfaces of the inner cover 1 and the inside of the opposite end surfaces of the outer cover 2 having a side larger than that of the first cover 1. Thus, the outer cover 2 is releaseably supported to the inner cover 1 in a condition in which the opposite end surface parts are engaged with each other, thereby it is possible to decrease the overall thickness.