Low-coherence interferometer device for determining information on the structure and/or the location of interfaces of an object comprising: - a polychromatic light source ; - an optical system for generating a measurement optical beam reflected by said object , and a reference optical beam; - a delay line for introducing a variable optical delay between the measurement optical beam and the reference optical beam; - an optical detection for combining the measurement optical beam and the reference optical beam and producing a spectral signal representative of an optical-power spectral density of the resulting interference signal; characterized in that it also comprises a control and processing module arranged in order to: - acquire a plurality of spectral signals for a plurality of optical delays; - determine, for each spectral signal, optical retardation information between interfering beams within a measurement range called spectral measurement range; - analyze the evolution of said optical retardations depending on the optical delay and assign the optical retardation or retardations determined from the different spectral signals to one or more curves called interface curves , corresponding to straight lines having unitary positive or negative gradients or zero gradients, depending on the respective optical delay of the acquisition of said spectral signals; and - deduce therefrom information on the structure and/or the location of interfaces of the object by using the interface curve or curves . - a polychromatic light source ; - an optical system for generating a measurement optical beam reflected by said object , and a reference optical beam; - a delay line for introducing a variable optical delay between the measurement optical beam and the reference optical beam; - an optical detection for combining the measurement optical beam and the reference optical beam and producing a spectral signal representative of an optical-power spectral density of the resulting interference signal; characterized in that it also comprises a control and processing module arranged in order to: - acquire a plurality of spectral signals for a plurality of optical delays; - determine, for each spectral signal, optical retardation information between interfering beams within a measurement range called spectral measurement range; - analyze the evolution of said optical retardations depending on the optical delay and assign the optical retardation or retardations determined from the different spectral signals to one or more curves called interface curves , corresponding to straight lines having unitary positive or negative gradients or zero gradients, depending on the respective optical delay of the acquisition of said spectral signals; and - deduce therefrom information on the structure and/or the location of interfaces of the object by using the interface curve or curves . - acquire a plurality of spectral signals for a plurality of optical delays; - determine, for each spectral signal, optical retardation information between interfering beams within a measurement range called spectral measurement range; - analyze the evolution of said optical retardations depending on the optical delay and assign the optical retardation or retardations determined from the different spectral signals to one or more curves called interface curves , corresponding to straight lines having unitary positive or negative gradients or zero gradients, depending on the respective optical delay of the acquisition of said spectral signals; and - deduce therefrom information on the structure and/or the location of interfaces of the object by using the interface curve or curves . <EOS>