A nozzle cap (1) is provided, which is formed from a rubber composition containing a rubber component including a diene rubber and a non-diene rubber, wherein the diene rubber is present in a proportion of 20 to 70 parts by mass based on 100 parts by mass of the total of the rubbers in the rubber composition. The nozzle cap (1) has a moderate gas transmission property and, hence, can be quickly sterilized by EOG sterilization and steam sterilization, quickly removed of residues by deaeration, and quickly dried in a shorter period after the steam sterilization. In addition, the nozzle cap (1) is less liable to be loosened due to increase in internal pressure and compression set and detached from the nozzle, and has a reduced leaching substance amount before and after the sterilization.
