A pressure detecting device (100, 200) which is mounted in a measurement target instrument, the device (100, 200) comprising: a strain inducer to which pressure of a pressure medium is applied and which generates strain in accordance with the pressure; and a strain detecting element that is bonded onto a surface opposite to a pressure receiving surface of the strain inducer, wherein the strain detecting element includes one or multiple central resistant bridge(s) sensitive to strain which are arranged at a central portion of the strain detecting element in a bonded surface direction, and one or multiple outer peripheral resistant bridges sensitive to strain which are arranged at an outer periphery of the central resistant bridge sensitive to strain, and wherein deformation of the strain detecting element caused by an external force when being mounted in the measurement target instrument is obtained through the multiple resistant bridges (300a, 300n) sensitive to strain, an error of detection pressure caused by the obtained deformation in a pressure value detected through the central resistant bridge sensitive to strain is corrected, and the corrected pressure value is referred to as a detection value of the pressure detecting device (100, 200), wherein the central resistant bridge sensitive to strain is arranged at a position corresponding to a site in the strain detecting element receiving first pressure which is applied from the pressure medium, wherein the outer peripheral resistant bridge sensitive to strain is arranged at a position corresponding to a site in the strain detecting element receiving second pressure which is lower than the first pressure, and wherein the fault signal is output when a detection pressure value of the central resistant bridge sensitive to strain becomes smaller than a detection pressure value of the outer peripheral resistant bridge sensitive to strain. a strain inducer to which pressure of a pressure medium is applied and which generates strain in accordance with the pressure; and a strain detecting element that is bonded onto a surface opposite to a pressure receiving surface of the strain inducer, wherein the strain detecting element includes one or multiple central resistant bridge(s) sensitive to strain which are arranged at a central portion of the strain detecting element in a bonded surface direction, and one or multiple outer peripheral resistant bridges sensitive to strain which are arranged at an outer periphery of the central resistant bridge sensitive to strain, and wherein deformation of the strain detecting element caused by an external force when being mounted in the measurement target instrument is obtained through the multiple resistant bridges (300a, 300n) sensitive to strain, an error of detection pressure caused by the obtained deformation in a pressure value detected through the central resistant bridge sensitive to strain is corrected, and the corrected pressure value is referred to as a detection value of the pressure detecting device (100, 200), wherein the central resistant bridge sensitive to strain is arranged at a position corresponding to a site in the strain detecting element receiving first pressure which is applied from the pressure medium, wherein the outer peripheral resistant bridge sensitive to strain is arranged at a position corresponding to a site in the strain detecting element receiving second pressure which is lower than the first pressure, and wherein the fault signal is output when a detection pressure value of the central resistant bridge sensitive to strain becomes smaller than a detection pressure value of the outer peripheral resistant bridge sensitive to strain.