An applicator is inserted into a living body and applies mixed solution to a region in the living body. The applicator includes a nozzle including an elongated nozzle main body to which gas and a plurality of kinds of liquids are supplied and a nozzle head provided at a distal end of the nozzle main body and configured to jet mixed solution of the gas and the plurality of kinds of liquids supplied to the nozzle main body, and a sheath in which the nozzle main body is fitted for relative movement along a longitudinal axial direction of the nozzle main body. A gap is provided between the nozzle main body and the sheath. The gap functions as an exhaust path for exhausting gas in the living body to the outside of the body when the pressure in the living body rises. The sheath has a plurality of side holes formed on a circumference thereof at a plurality of positions spaced by an equal interval along a longitudinal axial direction of the sheath, each of the side holes communicating with the gap.
