Provided are: ice which has excellent cooling capacity； a production method therefor； a method for producing a cooled article； and a refrigerant. Also provided are: ice in a non-separating state； and a production method therefor. The present invention pertains to ice which satisfies conditions (a) and (b) and is from a liquid that includes an aqueous solution comprising a solute. (a) The temperature of the ice after melting completely is less than 0 DEG C. (b) The rate of change of the solute concentration in the aqueous solution generated from the ice in the melting process is 30% or lower. The refrigerant of the present invention includes said ice. The refrigerant also includes water which comprises the same solute as the solute included in the ice, wherein the ratio of the concentration of the solute in the ice and the concentration of the solute in the water is preferably 75:25 to 20:80.本發明提供一種冷卻能力優異之冰、其製造方法、被冷卻物之製造方法、及冷媒。又，提供一種不分離之狀態之冰及其製造方法。 本發明係滿足以下(a)及(b)之條件之包含含有溶質之水溶液之液體之冰。 (a)融解完成時之溫度未達0℃ (b)於融解過程中自上述冰產生之水溶液之溶質濃度之變化率為30%以內 本發明之冷媒係包含上述冰者。冷媒較佳為包含含有與冰中所含之溶質相同之溶質之水，且冰中之上述溶質之濃度與水中之上述溶質之濃度之比為75：25～20：80。
