A pressure sensor includes a sensor chip that detects a pressure of a pressure medium; and a case that accommodates the sensor chip and has an inlet port connected with the outside, the case having a pressure inlet portion surrounding the inlet port. The pressure inlet portion is configured from: a front wall placed forward of the case with a clearance; a top wall and a pair of side walls, each which is connected to the front wall; and an opening introducing the pressure medium into the inlet port from a lower position with respect to the inlet port. The top wall is connected to the side walls and angled in entirety toward an upper position with respect to the inlet port. The front wall has an opening end configuring the opening, the opening end being recessed toward the top wall in an arc shape.