A pressure sensor is provided, which includes a pressure detector that has a pressure receiving surface in contact with a liquid, and detects a pressure of the liquid to a pressure receiving section, and a housing having a housing inner wall that demarcates a liquid chamber, wherein the housing inner wall is provided with an inflow hole, and an outflow hole, at least a part of a connecting portion, which is connected to the pressure receiving surface, of the housing inner wall is formed as an inner wall of the outflow hole, and the housing inner wall at the portion formed as the inner wall of the outflow hole protrudes more outward of the liquid chamber than the other connecting portion adjacent to the portion formed as the inner wall of the outflow hole.