A liquid sprayer is provided to secure good deposition efficiency by keeping low air pressure by spraying liquid through a vane of a rotary cup and to improve work environment by reducing noise and scattering of paint particle. A liquid sprayer is composed of a rotary cup(50) having a vane installed on the outer peripheral surface of one end and a longitudinal liquid passage formed in the center; a nozzle(90) for containing the vane of the rotary cup; a driving unit for selectively rotating the rotary cup; and a liquid containing unit(30) for supplying liquid to the liquid passage of the rotary cup. An inner diameter of the liquid passage of the rotary cup is gradually expanded toward one end.
