An electrical impedance tomography EIT apparatus which has a plurality of electrodes 4 which can be attached to a body to enable the impedance distribution of the body on the plane of the electrodes to be reconstructed with a reconstruction algorithm. By programming, the control unit 10 of the EIT apparatus continuously determines at least one property el, ..., em, such as signal to noise ratio, crosstalk, signal drift, phase distribution of frequency spectra, at a time from the measurement signals U1, ..., UM on all the measurement channels and to correct measurement signals on the measurement channels on the basis of the properties or to adapt the reconstruction algorithm on the basis of the properties.
