A latent heat accumulation system uses latent heat for air-conditioning. The latent heat accumulation system includes a tank, supplying section, injecting section, drawing section and collecting section. The tank has a liquid storing section for storing Fluorinate (trade name) in the lower portion thereof, storing water which is cooled by ice via a boundary surface with Fluorinate in the middle portion thereof and storing the ice together with the water in the upper portion thereof. The supplying section supplies the water into the liquid storing section. The injecting section injects Fluorinate cooled to a preset temperature into the water stored in the liquid storing section. The drawing section draws out the water which is stored in the liquid storing section and cooled by the ice to the exterior of the tank as an air-conditioning heat accumulation medium. The collecting section collects a mixed fluid of the water and Fluorinate from the lower portion of the liquid storing section.