PURPOSE: To make the pulling force of a trigger light and to enable even a children having no force at fingers to play by providing a trigger having a contact pressure part in contact with a presser to open a water channel by rotating the presser.

CONSTITUTION: When the trigger part 8a of a trigger 8 is pulled toward the operater, a contact part 8b is rotated at the rotary part 8c as a center. At this time, since the length of the part 8b is shorter than the part 8a, the force for moving the part 8a is strongly operated at the part 8b by the application of a lever. Since the part 8b separates the entire presser 6 from a water channel by the energizing force of a leaf spring 7, the end 6a is separated from the channel 5 to open the channel 5. Since the water in the channel 5 is applied by the pressure, it is injected from an outlet 10. Accordingly, the trigger is not directly biased to the channel side by the spring, and since the contact part is shorter than the trigger part, the trigger part can be pulled simply even by a small child's force.