<p>Provided is a piston cylinder unit which can be universally applied to different types of trigger sprays by modularizing a main function structure portion. The piston cylinder unit (A) is incorporated in a trigger spray wherein a piston portion (23) is slid in upward and downward directions by the rotation of a trigger, to pressurize a liquid within the cylinder and spray the liquid to the outside through a nozzle portion (21). The piston cylinder unit (A) is characterized in that a nozzle piston structure (2) provided with a joint portion to joint the nozzle portion (21) and the piston portion (23), and a cylinder portion (1) are modularized as a unit.</p>
