Provided are a latent heat storage material that changes the phase within a prescribed temperature range, and a cold storage tool, a logistic packaging container, and a food cold storage tool each using the latent heat storage material, and a cooling method. The latent heat storage material includes a tetrabutylammonium ion and a bromide ion constituting tetrabutylammonium bromide, a potassium ion and a nitrate ion constituting potassium nitrate, and water. The molar ratio of potassium nitrate to tetrabutylammonium bromide is 0.3 or more and 1.3 or less, and the molar ratio of water to tetrabutylammonium bromide is 22 or more and 32 or less.