An applicator is insertable into a living body to apply 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 at a distal end of the nozzle main body to jet mixed solution of the gas and the plurality of kinds of liquids supplied to the nozzle main body. The nozzle main body is positioned in a sheath for relative axial movement. A gap exists between the nozzle main body and the sheath to exhaust 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, each of which communicates with the gap.
