A method of applying a liquid or powder in a body cavity of a living body involves positioning the distal portion of an applicator in the living body, using an applicator that includes an outer tube and a nozzle having an elongated nozzle main body and a nozzle head at the distal end side of the nozzle main body. The method also includes relatively moving the outer tube and the nozzle so a curved section of the nozzle main body moves proximally relative to the outer tube and enters the outer tube to adjust the direction in which the nozzle is facing, conveying the liquid/powder through the nozzle main body and to the nozzle head, expelling the liquid or the powder from the nozzle head toward a surface in the body cavity, and discharging gas in the body cavity into a longitudinally extending gap and to outside the body cavity.