A heliostat capable of collecting light with high efficiency and having reduced manufacturing and installation costs; and a method of controlling the heliostat. The heliostat includes a reflecting mirror configured to reflect sunlight; and a support mechanism configured to tiltably support the reflecting mirror. The support mechanism has a single supporting column and first and second cylinders. The reflecting mirror is supported at its back surface by a supporting column upper end of the supporting column, a first cylinder upper end of the first cylinder and a second cylinder upper end of the second cylinder in a tiltable manner, which are arranged to form a triangle on the back surface of the reflecting mirror. A gimbal bearing connects the supporting column upper end and the reflecting mirror, the gimbal bearing being configured to be tiltable in two axial directions intersecting with each other.