Abstract: A quantum interference apparatus includes a space and an alkali-metal atomic cell. A static magnetic field having a specific direction and a specific intensity is applied to the space. The alkali-metal atomic cell is disposed inside the space. Alkali-metal atoms are encapsulated in the alkali-metal atomic cell. As a static magnetic field is applied to the alkali-metal atomic cell and excitation light having at least two different frequency components is applied thereto, a quantum interference state of the alkali-metal atoms is formed. Among the frequency components of the excitation light, a frequency component that participates in the formation of the quantum interference state is light containing linearly-polarized lights having the same polarization direction as each other. The static magnetic field applied to the space is adjusted so that fluctuations of a transition frequency between ground levels forming the quantum interference state with respect to the magnetic field is suppressed.