A body support device includes: a first support part that is attached to a thigh back of a wearer so that a first end thereof is located close to a hip of the wearer and a second end thereof is located close to a knee of the wearer； a second support part that is attached to a shin of the wearer so that a first end thereof is located close to the knee of the wearer and a second end thereof is located close to a foot of the wearer； a grounding part located close to the foot of the wearer； a first rotary part that connects the second end of the first support part with the first end of the second support part and rotates the first and second support parts； and a second rotary part that connects the second end of the second support part with an upper end of the grounding part and rotates the second support part and the grounding part. The first rotary part restricts the rotation in a direction that brings the thigh back and a calf of the wearer closer to each other to within a predetermined angle, and the second rotary part restricts the rotation in a direction that brings the shin and the instep of the foot of the wearer closer to each other to within a predetermined angle. The grounding part comes into contact with the ground in a state in which the rotation of the first rotary part or the rotation of the second rotary part is at least restricted.
