A sensor for measuring pressures in low-viscosity media for use in injection molding includes a housing with an axis A, a flat end face to be exposed to a pressure space, and a diaphragm that is arranged on the end face and is permanently connected to the housing. A measuring element that can infer a pressure prevailing in the pressure space on the basis of deflection of the diaphragm is arranged behind the diaphragm. A pressure sleeve that is tightly connected to the sensor on the end face and is arranged at a distance from the housing with a gap behind this connection is arranged coaxially with the housing axis A outside the housing. The gap extends axially further across the measuring element than the region of the force path in the direction away from the pressure space.