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.