To provide a cold insulation box which includes a drain part for preventing a lid body from getting dirty in draining, enabling opening/closing the lid body by simple operation, and preventing the lid body from being opened unexpectedly.SOLUTION: A cold insulation box includes a drain part 10 provided in a lateral wall 3A of a body 3, and discharging water in the inside to the outside. The drain part 10 comprises: a cylindrical body 20 communicated to the inside of the body and becoming a discharge flow channel of water accumulated in the inside of the body； a substrate 30 integrated with the cylindrical body； and a lid body 50 supported rotatably to the substrate 30, and opening/closing the opening of the cylindrical body 20. The substrate 30 and the lid body 50 are engaged by elastically engageable engaging means. The lid body 50 is provided with an operation member 55 for releasing elastic engagement by the engaging means, and there is provided a lock member 81 to be operated between a position of preventing release of the elastic engagement by the engaging means and a position of allowing release of elastic engagement when the operation member 55 is in a closed state.SELECTED DRAWING: Figure 3【課題】水抜きをする際に蓋体が汚れることはなく、簡単な操作で蓋体の開閉が行えるとともに不用意に蓋体が開くことのない水抜き部を備えた保冷箱を提供する。【解決手段】本体３の側壁３Ａに設けられ、内部の水を外部に放出する水抜き部１０を備えた保冷箱において、水抜き部１０は、本体の内部に連通し、本体の内部に溜まった水の放出流路となる筒体２０と、筒体と一体化される支持体３０と、支持体３０に対して回動可能に支持され、かつ、筒体２０の開口を開閉する蓋体５０と、を有している。支持体３０と蓋体５０は、弾性係合可能な係合手段によって係合され、蓋体５０に、係合手段による弾性係合を解除する操作部材５５を設けており、操作部材５５が閉状態にあるとき、係合手段による弾性係合の解除を防止する位置と弾性係合の解除を許容する位置との間で操作されるロック部材８１を有する。【選択図】図３
