An ophthalmic apparatus (1, 2) configured to measure a subject eye by using an optical interferometry, the ophthalmic apparatus (1, 2) comprising: a light source of wavelength sweeping type; a reference optical system configured to irradiate a reference surface with light from the light source and guide reflected light as reference light therefrom; a calibration optical system configured to guide the light from the light source so as to acquire calibration light from the light from the light source; a light receiving element configured to receive calibration interference light, the calibration interference light being a combination of the calibration light and the reference light; a signal processor configured to sample a calibration interference signal, the calibration interference signal being outputted from the light receiving element when the light receiving element receives the calibration interference light; a processor; and a memory storing computer-readable instructions therein, wherein a frequency of the light from the light source changes cyclically, characterized in that the signal processor is configured to sample the calibration interference signal in at least a first frequency band and a second frequency band within an entire frequency band that corresponds to one cycle of change in the frequency of the light from the light source, the second frequency band being different from the first frequency band, the first frequency band being used for measuring a specific region of the subject eye, the second frequency band being used for measuring the specific region of the subject eye, and the first and second frequency bands being used when tomographic image for a same subject eye is generated, and the computer-readable instructions, when executed by the processor, cause the ophthalmic apparatus (1, 2) to calculate a difference between a first waveform and a second waveform, the first waveform being a waveform of the calibration interference signal that is sampled in the first frequency band and Fourier transformed, the second waveform being a waveform of the calibration interference signal that is sampled in the second frequency band and Fourier transformed. a light source of wavelength sweeping type; a reference optical system configured to irradiate a reference surface with light from the light source and guide reflected light as reference light therefrom; a calibration optical system configured to guide the light from the light source so as to acquire calibration light from the light from the light source; a light receiving element configured to receive calibration interference light, the calibration interference light being a combination of the calibration light and the reference light; a signal processor configured to sample a calibration interference signal, the calibration interference signal being outputted from the light receiving element when the light receiving element receives the calibration interference light; a processor; and a memory storing computer-readable instructions therein, wherein a frequency of the light from the light source changes cyclically, characterized in that the signal processor is configured to sample the calibration interference signal in at least a first frequency band and a second frequency band within an entire frequency band that corresponds to one cycle of change in the frequency of the light from the light source, the second frequency band being different from the first frequency band, the first frequency band being used for measuring a specific region of the subject eye, the second frequency band being used for measuring the specific region of the subject eye, and the first and second frequency bands being used when tomographic image for a same subject eye is generated, and the computer-readable instructions, when executed by the processor, cause the ophthalmic apparatus (1, 2) to calculate a difference between a first waveform and a second waveform, the first waveform being a waveform of the calibration interference signal that is sampled in the first frequency band and Fourier transformed, the second waveform being a waveform of the calibration interference signal that is sampled in the second frequency band and Fourier transformed.