A support device comprising: a force measurement sensor structure (10,10a,10b) comprising: first and second elastic members; (3a,3b) and an intermediate element supported between the first and second elastic members; a drive unit which is configured to vary a load applied to the intermediate element from the first and second elastic members of the force measurement sensor structure; a control unit which is configured to control the drive unit; and a wearable unit which a user wears on user's body; wherein the force measurement sensor structure includes: a shaft having a first end section and a second end section; the intermediate element movably provided between the first end section and the second end section along the shaft; the first elastic member provided between the first end section and the intermediate element along the shaft; the second elastic member provided between the second end section and the intermediate element along the shaft; a linear potentiometer connected to the intermediate element and configured to detect a position of the intermediate element in one dimensional direction along the shaft; and a gripping unit (12,12a) connected to the intermediate element and configured to transmit a force to the intermediate element in an interlocking manner with a movement of an upper limb or a lower limb of the user, the wearable unit includes: a front frame provided on a front side of the user; a rear frame connected to the front frame, provided on a rear side of the user, and supporting the drive unit; and an arm attached on the front frame, the arm suspending a wire which connects the force measurement sensor structure and the drive unit to each other, wherein the first and second elastic members are configured to support the intermediate element, are capable of applying a load to the intermediate element in directions opposite to each other in one dimensional direction along the shaft, the linear potentiometer detects a position of the intermediate element in one dimensional direction along the shaft to measure a force applied to the intermediate element, and the control unit is configured to control the drive unit depending on the measured force applied to the intermediate element. a force measurement sensor structure (10,10a,10b) comprising: first and second elastic members; (3a,3b) and an intermediate element supported between the first and second elastic members; a drive unit which is configured to vary a load applied to the intermediate element from the first and second elastic members of the force measurement sensor structure; a control unit which is configured to control the drive unit; and a wearable unit which a user wears on user's body; wherein the force measurement sensor structure includes: a shaft having a first end section and a second end section; the intermediate element movably provided between the first end section and the second end section along the shaft; the first elastic member provided between the first end section and the intermediate element along the shaft; the second elastic member provided between the second end section and the intermediate element along the shaft; a linear potentiometer connected to the intermediate element and configured to detect a position of the intermediate element in one dimensional direction along the shaft; and a gripping unit (12,12a) connected to the intermediate element and configured to transmit a force to the intermediate element in an interlocking manner with a movement of an upper limb or a lower limb of the user, a shaft having a first end section and a second end section; the intermediate element movably provided between the first end section and the second end section along the shaft; the first elastic member provided between the first end section and the intermediate element along the shaft; the second elastic member provided between the second end section and the intermediate element along the shaft; a linear potentiometer connected to the intermediate element and configured to detect a position of the intermediate element in one dimensional direction along the shaft; and a gripping unit (12,12a) connected to the intermediate element and configured to transmit a force to the intermediate element in an interlocking manner with a movement of an upper limb or a lower limb of the user, the wearable unit includes: a front frame provided on a front side of the user; a rear frame connected to the front frame, provided on a rear side of the user, and supporting the drive unit; and an arm attached on the front frame, the arm suspending a wire which connects the force measurement sensor structure and the drive unit to each other, a front frame provided on a front side of the user; a rear frame connected to the front frame, provided on a rear side of the user, and supporting the drive unit; and an arm attached on the front frame, the arm suspending a wire which connects the force measurement sensor structure and the drive unit to each other, wherein the first and second elastic members are configured to support the intermediate element, are capable of applying a load to the intermediate element in directions opposite to each other in one dimensional direction along the shaft, the linear potentiometer detects a position of the intermediate element in one dimensional direction along the shaft to measure a force applied to the intermediate element, and the control unit is configured to control the drive unit depending on the measured force applied to the intermediate element.