A detecting sensor comprising: a magnet that generates a magnetic field; a plurality of sensor elements (30A, 30B) that detect a change in the magnetic field generated by the magnet; and a housing having first, second, third and fourth holding sections (34, 36, 33, 35), the housing holding the magnet and the sensor elements (30A, 30B), wherein each of the plurality of sensor elements (30A, 30B) includes a body and a terminal projecting from the body, and the plurality of sensor elements (30A, 30B) are held in the housing with the bodies overlapped with each other in a state in which the terminals project in a same direction from the bodies, wherein the sensor elements (30A, 30B) are held so as to be sandwiched between the first and third holding sections (34, 33) that abut against only a portion of a surface of the body of a first sensor element on one side of the plurality of sensor elements (30A, 30B) whose bodies are overlapped with each other, and the second and fourth holding sections (36, 35) that abut against only a portion of a surface of the body of a second sensor element on another side of the plurality of sensor elements (30A, 30B), the third holding section being formed so as to extend along two sides parallel to each other of the body section of the first sensor element, the fourth holding section being formed so as to extend along two sides parallel to each other of the body section of the second sensor element, the first holding section having a columnar shape arranged substantially in a center portion of the body section of the first sensor element, and extending toward the body section from a perpendicular direction, a distal end portion of the first holding section abutting against the center portion of the surface of the body section, the second holding section being provided so as to extend along the body section in a direction perpendicular to the fourth holding section (35, 35) located on said two sides of the body section of the second sensor element, the second holding section abutting against the surface of the body section of the second sensor element in a substantially H shape. together with the fourth holding sections (35, 35) on said two sides. a magnet that generates a magnetic field; a plurality of sensor elements (30A, 30B) that detect a change in the magnetic field generated by the magnet; and a housing having first, second, third and fourth holding sections (34, 36, 33, 35), the housing holding the magnet and the sensor elements (30A, 30B), wherein each of the plurality of sensor elements (30A, 30B) includes a body and a terminal projecting from the body, and the plurality of sensor elements (30A, 30B) are held in the housing with the bodies overlapped with each other in a state in which the terminals project in a same direction from the bodies, wherein the sensor elements (30A, 30B) are held so as to be sandwiched between the first and third holding sections (34, 33) that abut against only a portion of a surface of the body of a first sensor element on one side of the plurality of sensor elements (30A, 30B) whose bodies are overlapped with each other, and the second and fourth holding sections (36, 35) that abut against only a portion of a surface of the body of a second sensor element on another side of the plurality of sensor elements (30A, 30B), the third holding section being formed so as to extend along two sides parallel to each other of the body section of the first sensor element, the fourth holding section being formed so as to extend along two sides parallel to each other of the body section of the second sensor element, the first holding section having a columnar shape arranged substantially in a center portion of the body section of the first sensor element, and extending toward the body section from a perpendicular direction, a distal end portion of the first holding section abutting against the center portion of the surface of the body section, the second holding section being provided so as to extend along the body section in a direction perpendicular to the fourth holding section (35, 35) located on said two sides of the body section of the second sensor element, the second holding section abutting against the surface of the body section of the second sensor element in a substantially H shape. together with the fourth holding sections (35, 35) on said two sides.