Disclosed is an atomic interferometer including a source of atoms, a laser source and a magnetic field generating device, a polarizer, a system for adjusting a detuning between two optical frequencies of the incident laser beam, a two-dimensional diffraction grating arranged in such a way as to receive the incident laser beam and to form by diffraction at least three diffracted beams, a controller configured to select a combination of an optical frequency detuning, a polarization state and a magnetic field, the combination being adapted to select a first pair of laser beams among the pairs of beams formed from the incident laser beam and the diffracted beams, the pair of laser beams being applied in such a way as to interact with the cloud of atoms by multi-photon transitions and to detect an acceleration of the cloud of atoms along a measurement direction.