PROBLEM TO BE SOLVED: To provide a foam retention improving agent capable of improving the foam retention of a beverage even at low temperatures.SOLUTION: The foam retention improving agent is used which contains frozen micro particles of a carbonated beverage containing gain decomposition products. Preferably, the carbonated beverage containing the grain decomposition product is a beer-based beverage.【課題】低温であっても飲料の泡持ち向上可能な泡持ち向上剤の提供。【解決手段】穀類分解物含有発泡性飲料の凍結微粒子を含む泡持ち向上剤を用いる。【選択図】なし