To provide a trigger type liquid jetting device wherein an excessive force is prevented from causing a bad influence by suppressing transmission of the force as much as possible even if the excessive force acts on an arm of a nozzle cover.

In the trigger type liquid jetting device provided with a body (2) equipped with a pump to suck and pressurize the liquid in a container by pulling a control lever (1), a jetting nozzle (3) that jets the liquid sent under pressure via a supplying passage of the body (2) rotatively supported at the top end of the body (2) and an arm (4b) to switch over the nozzle opening to an opened state or a closed state and prevents the pull of the control lever (1) by rotating the jetting nozzle (3) around its axial center (L), the arm (4b) is rich in flexibility so as to follow the force inducing the compulsory pulling movement of the control lever (1) while preventing the pull of the control lever (1) by being located at the front side of the control lever (1) in a closed state of the nozzle opening.