A pressure sensor, comprising: a pressure detector having a pressure detecting element and a sheet, the sheet having a pressure receiving surface in contact with a liquid, the pressure detector detects a pressure of the liquid on a pressure receiving section included in the pressure receiving surface; and a housing having a housing inner wall that together with the pressure receiving surface demarcates a liquid chamber, wherein the housing inner wall is provided with an inflow hole (12a, 12b) that causes the liquid to flow into the liquid chamber, and an outflow hole that causes the liquid to flow out of the liquid chamber, wherein the housing inner wall has a bottom surface that faces the pressure receiving surface and a side surface for connecting the bottom surface and the pressure receiving surface to demarcate the liquid chamber, wherein the side surface comprises a connecting portion that is connected to the pressure receiving surface, wherein, in a position in which the outflow hole is present, the connecting portion is formed as an inner wall of the outflow hole, and wherein the connecting portion, which is formed as the inner wall of the outflow hole, protrudes more outward of the liquid chamber than the other connecting portion which is adjacent to the connecting portion, whereby outward refers to a direction toward the side surface of the housing inner wall from a center line direction substantially orthogonal to the pressure receiving surface, characterized in that a plan view of the pressure receiving surface is substantially circular, and a conditional expression as follows is satisfied: − 0.5 ≤ r 1 − r 2 / r 3 ≤ 0.9 where r1: a distance from a center of the pressure receiving surface to an end portion of the pressure receiving surface, r2: a distance from the center of the pressure receiving surface to a center of the outflow hole, and r3: a distance from the center of the outflow hole to an inner wall of the outflow hole. a pressure detector having a pressure detecting element and a sheet, the sheet having a pressure receiving surface in contact with a liquid, the pressure detector detects a pressure of the liquid on a pressure receiving section included in the pressure receiving surface; and a housing having a housing inner wall that together with the pressure receiving surface demarcates a liquid chamber, wherein the housing inner wall is provided with an inflow hole (12a, 12b) that causes the liquid to flow into the liquid chamber, and an outflow hole that causes the liquid to flow out of the liquid chamber, wherein the housing inner wall has a bottom surface that faces the pressure receiving surface and a side surface for connecting the bottom surface and the pressure receiving surface to demarcate the liquid chamber, wherein the side surface comprises a connecting portion that is connected to the pressure receiving surface, wherein, in a position in which the outflow hole is present, the connecting portion is formed as an inner wall of the outflow hole, and wherein the connecting portion, which is formed as the inner wall of the outflow hole, protrudes more outward of the liquid chamber than the other connecting portion which is adjacent to the connecting portion, whereby outward refers to a direction toward the side surface of the housing inner wall from a center line direction substantially orthogonal to the pressure receiving surface, characterized in that a plan view of the pressure receiving surface is substantially circular, and a conditional expression as follows is satisfied: − 0.5 ≤ r 1 − r 2 / r 3 ≤ 0.9 where r1: a distance from a center of the pressure receiving surface to an end portion of the pressure receiving surface, r2: a distance from the center of the pressure receiving surface to a center of the outflow hole, and r3: a distance from the center of the outflow hole to an inner wall of the outflow hole. r1: a distance from a center of the pressure receiving surface to an end portion of the pressure receiving surface, r2: a distance from the center of the pressure receiving surface to a center of the outflow hole, and r3: a distance from the center of the outflow hole to an inner wall of the outflow hole.