There is provided a syringe filled with a resin composition which prevents a barrel cap from being detached due to temperature change during storage or during transportation, a production method thereof, and a storage method thereof. This syringe filled with the resin composition includes a syringe having a syringe barrel, a resin composition filling the syringe barrel, a plunger inserted in the syringe barrel, a barrel cap blocking an opening of the syringe barrel, and a spatial part between the plunger and the barrel cap in the syringe barrel. The pressure of the spatial part in a frozen state is 50 kPa to 92 kPa.