A surface stress sensor comprising: a membrane configured to be bent by applied surface stress; a frame member configured to be separated from the membrane and surround the membrane when viewed from a thickness direction of the membrane ; at least a pair of coupling portions arranged at positions sandwiching the membrane when viewed from the thickness direction and configured to couple the membrane and the frame member ; a flexible resistor configured to be disposed on at least one of the coupling portions and have a resistance value changing according to bending induced in the coupling portion ; and a support base member configured to be connected to the frame member , wherein a cavity portion is disposed between the membrane and the support base member , and between the coupling portions and the support base member , characterized in that the support base member overlaps the membrane and the coupling portions when viewed from the thickness direction, further comprising a package substrate connected to a face of the support base member on an opposite side to a face of the support base member facing the membrane , wherein the support base member and the package substrate are connected to each other by a connecting portion arranged at a position at which the connecting portion overlaps at least a portion of the membrane when viewed from the thickness direction, and when viewed from the thickness direction of the membrane , an area of the connecting portion is smaller than an area of the membrane . a membrane configured to be bent by applied surface stress; a frame member configured to be separated from the membrane and surround the membrane when viewed from a thickness direction of the membrane ; at least a pair of coupling portions arranged at positions sandwiching the membrane when viewed from the thickness direction and configured to couple the membrane and the frame member ; a flexible resistor configured to be disposed on at least one of the coupling portions and have a resistance value changing according to bending induced in the coupling portion ; and a support base member configured to be connected to the frame member , wherein a cavity portion is disposed between the membrane and the support base member , and between the coupling portions and the support base member , characterized in that the support base member overlaps the membrane and the coupling portions when viewed from the thickness direction, further comprising a package substrate connected to a face of the support base member on an opposite side to a face of the support base member facing the membrane , wherein the support base member and the package substrate are connected to each other by a connecting portion arranged at a position at which the connecting portion overlaps at least a portion of the membrane when viewed from the thickness direction, and when viewed from the thickness direction of the membrane , an area of the connecting portion is smaller than an area of the membrane . characterized in that the support base member overlaps the membrane and the coupling portions when viewed from the thickness direction, further comprising a package substrate connected to a face of the support base member on an opposite side to a face of the support base member facing the membrane , wherein the support base member and the package substrate are connected to each other by a connecting portion arranged at a position at which the connecting portion overlaps at least a portion of the membrane when viewed from the thickness direction, and when viewed from the thickness direction of the membrane , an area of the connecting portion is smaller than an area of the membrane . <EOS>