The tiltable-body apparatus including a frame member, a tiltable body, and a pair of torsion springs having a twisting longitudinal axis. The torsion springs are disposed along the twisting longitudinal axis opposingly with the tiltable body being interposed, support the tiltable body flexibly and rotatably about the twisting longitudinal axis relative to the frame member, and include a plurality of planar portions, compliant directions of which intersect each other when viewed along a direction of the twisting longitudinal axis. A center of gravity of the tiltable body is positioned on the twisting longitudinal axis of the torsion springs.