In order to enable long-term stabilization of rapamycin contained in a liquid formulation, a formulation sealing vessel of the present invention includes: a sealed vessel body in which a liquid formulation containing 2% (w/w) rapamycin or a salt thereof, 94% (w/w) polyethylene glycol, and 4% (w/w) ethanol is sealed, the sealed vessel body having a volume of 0.1 mL to 1.0 mL, the liquid formulation containing no antioxidant, and the liquid formulation having a total volume of 0.02 mL to 1.0 mL.