The invention relates to a device for limiting the injection pressure of a cannula, comprising a housing (10), an inlet (12) of the housing (10) for introducing a fluid at an inlet pressure, an outlet (18) of the housing (10) for supplying the fluid to the cannula, a through-flow channel of the housing (10) joining the inlet (12) and the outlet (18), and a piston (22) guided in the housing (10) which is impinged by the pressure of the fluid in the through-flow channel, and which can be moved against a spring force via this pressure. A closure element (30, 66) is arranged on the piston (22), which is located in the flow cross-section of the through-flow channel, wherein the closure element (30, 66) releases the flow cross-section when the pressure of the fluid impinging the piston (22) is below a value predetermined by the spring force, and blocks the flow cross-section when the pressure of the fluid impinging the piston (22) exceeds this predetermined value, and moves the piston (22) against the spring force.
