Pressure sensor

Pressure sensor comprising a housing, a membrane arranged in said housing and being deflectable by the pressure to be measured, a light source (LED) having an optical axis, a light detector having an optical axis, a light blocker that is coupled to the membrane and that can be deflected thereby, said blocker being arranged in the beam path of the light source, wherein the light source and the light detector are arranged inside the housing such that their optical axes lie parallel to one another, a first reflection surface assigned to the light source, and a second reflection surface assigned to the light detector, wherein an uninterrupted beam path from the light source through both reflection surfaces to the light detector is obtained and the light blocker is arranged between both reflection surfaces, wherein a holding device is provided which is insertable into the housing and comprises a receiving opening for each of the light source and the light detector, the holding device supporting the first and the second reflection surfaces in the region of the respective receiving opening and being made of a transparent material.