A pressure sensor is equipped with a body including a fluid passage in the interior thereof, a holder connected to one end of the body, and a ceramic sensor accommodated in the interior of the holder. Plural protrusions are disposed on an outer edge portion of an end surface of the sensor, which is pressed by the holder. In addition, when the holder is fastened with respect to the body, in a state in which a pressing portion of the holder abuts against the protrusions, a fastening force is applied in an axial direction, and the sensor is fixed.