An applicator which is used by being inserted into a living body includes: a nozzle which has a longer nozzle main body, and a nozzle head, which is provided on a front end side of the nozzle main body and through which liquid together with gas is expelled, with a curved section, which is curved or bent and has flexibility, being formed on the front end portion of the nozzle main body; and an outer tube through which the nozzle main body is inserted so as to be movable along a longitudinal direction thereof and a curve angle of the curved section is changed by inserting the curved section, thereby adjusting a direction of the nozzle head relative to an axis of the nozzle main body, wherein a gap is formed along the longitudinal direction between the outer tube and the nozzle, and wherein the gap functions as a discharge path for discharging the gas within the body cavity via the gap to the outside of the body when the body pressure within the body cavity rises.