PROBLEM TO BE SOLVED: To provide a cold storage material small in overcooling for reducing electrical energy needed for cooling.SOLUTION: There is provided a latent heat cold storage material containing water, urea and an urea derivative, where the urea derivative contains 1,1-dimethyl urea and 1,3-dimethyl urea, blended ratio (mass ratio) of the 1,1-dimethyl urea and 1,3-dimethyl urea is 2:3 to 3:2, content of the urea is 25 to 40 wt.% based on weight of water and content of the urea derivative is 10 to 75 wt.% based on weight of the urea.SELECTED DRAWING: Figure 1【課題】冷却に必要な電気エネルギーの削減を目的とした過冷却の小さい冷凍用蓄冷材を提供する。【解決手段】水、尿素および尿素誘導体を含み、前記尿素誘導体が１，１－ジメチル尿素および１，３－ジメチル尿素を含み、１，１－ジメチル尿素と１，３－ジメチル尿素の配合比（重量比）が２：３～３：２であり、尿素の含有量が水の重量に対して２５～４０ｗｔ％であり、尿素誘導体の含有量が尿素の重量に対して１０～７５ｗｔ％である、潜熱蓄冷材。【選択図】図１
