A force detecting device comprising: a first base section; a second base section; and a first sensor device and a second sensor device each including a piezoelectric element sandwiched by the first base section and the second base section in a first and second sandwiching direction, respectively, and configured to detect external forces applied to the first base section and the second base section, each of the piezoelectric elements including first (121, 123) and second (141, 143) boards laminated in a laminating direction which is parallel to the respective sandwiching direction, wherein the first base section includes a first attachment surface for being fixed to a measurement target and the second base section includes a second attachment surface for being fixed to the measurement target, and each of the piezoelectric elements is set such that a normal (NL1, NL2) of the first attachment surface or the second attachment surface and the laminating direction of the first board and the second board of the respective piezoelectric element are orthogonal to each other, characterized in that the first (121, 123) and the second (141, 143) boards of each piezoelectric element are formed by a Y-cut quartz plate having an x axis, a y axis and a z axis, which are crystal axes orthogonal to one another, and for each piezoelectric element, the x axis of the first board and the x axis of the second board cross each other and the z axis of the first board and the z axis of the second board cross each other, and an A axis, a B axis, and a C axis, which are orthogonal coordinate axes, are set as coordinate axes in which the C axis is in a direction parallel to an intersection line of a first plane orthogonal to the first sandwiching direction of the first sensor device and a second plane orthogonal to the second sandwiching direction of the second sensor device, and the external forces applied to the first base section and the second base section are detected as components of external forces in the three axis directions. a first base section; a second base section; and a first sensor device and a second sensor device each including a piezoelectric element sandwiched by the first base section and the second base section in a first and second sandwiching direction, respectively, and configured to detect external forces applied to the first base section and the second base section, each of the piezoelectric elements including first (121, 123) and second (141, 143) boards laminated in a laminating direction which is parallel to the respective sandwiching direction, wherein the first base section includes a first attachment surface for being fixed to a measurement target and the second base section includes a second attachment surface for being fixed to the measurement target, and each of the piezoelectric elements is set such that a normal (NL1, NL2) of the first attachment surface or the second attachment surface and the laminating direction of the first board and the second board of the respective piezoelectric element are orthogonal to each other, characterized in that the first (121, 123) and the second (141, 143) boards of each piezoelectric element are formed by a Y-cut quartz plate having an x axis, a y axis and a z axis, which are crystal axes orthogonal to one another, and for each piezoelectric element, the x axis of the first board and the x axis of the second board cross each other and the z axis of the first board and the z axis of the second board cross each other, and an A axis, a B axis, and a C axis, which are orthogonal coordinate axes, are set as coordinate axes in which the C axis is in a direction parallel to an intersection line of a first plane orthogonal to the first sandwiching direction of the first sensor device and a second plane orthogonal to the second sandwiching direction of the second sensor device, and the external forces applied to the first base section and the second base section are detected as components of external forces in the three axis directions.