THz measuring method for measuring a measured object (8, 18, 28, 38), comprising at least the following steps: - calibration measurement with emitting a THz transmission beam through an empty measuring space towards a main reflector along an optical axis, reflection of the THz transmission beam at the main reflector along the optical axis back to the THz transceiver and detecting a calibration main reflection peak at a calibration point in time, - introducing a measured object (8, 18, 28, 38) including wall regions into the measuring space, - object measurement with emitting the THz transmission beam from the THz transceiver along the optical axis through the measuring space and the measured object (8, 18, 28, 38) towards the main reflector, reflection of the THz transmission beam along the optical axis back to the THz transceiver and detecting a measuring main reflection peak (Pt) of the object measurement at a main reflection point in time, - determining a total time delay (tP1-tP0) of the main reflection time in relation to the calibration time, - allocating the total time delay (tP1-tP0) to a sum of the temporal delays of the THz transmission beam in the wall regions of the measured object (8, 18, 28, 38) and determining geometric layer thicknesses of the measured object, where the THz transmission beam passes through boundary surfaces (8a, 8b; 18a, 18b; 28a, 28b; 38a, 38b) of the measured object (8, 18, 28, 38) thereby generating partial reflections beams and generating, upon being detected, a signal amplitude with: - the main reflection peak at the main reflection time - and measuring peaks (P1, P2, P3, P4. P5, P6) of boundary surfaces oriented perpendicular to the optical axis at partial reflection times (t1, t2, t3, t4, t5, t6), - where geometric layer thicknesses (WTij) of the measured object (8, 18, 28, 38) along the optical axis are determined from temporal differences of the determined partial reflection times (t1, t2, t3, t4, t5, t6) of the measuring peaks (P1, P2, P3, P4. P5, P6) and its refraction index (n0, n1) as air gaps and/or wall regions of the measured object, characterized in that, in the case that in relation to at least one boundary surface (8a; 11a; 328a, 328b; 38a, 38b) no measuring peak in the signal amplitude is determined, a geometric layer thickness (WT34, WT12) of a wall region is determined by determining the total time delay (tP1-tP0) and the allocation of the total time delay (tP1-tP0) to the sum of temporal delays in the wall regions. - calibration measurement with emitting a THz transmission beam through an empty measuring space towards a main reflector along an optical axis, reflection of the THz transmission beam at the main reflector along the optical axis back to the THz transceiver and detecting a calibration main reflection peak at a calibration point in time, - introducing a measured object (8, 18, 28, 38) including wall regions into the measuring space, - object measurement with emitting the THz transmission beam from the THz transceiver along the optical axis through the measuring space and the measured object (8, 18, 28, 38) towards the main reflector, reflection of the THz transmission beam along the optical axis back to the THz transceiver and detecting a measuring main reflection peak (Pt) of the object measurement at a main reflection point in time, - determining a total time delay (tP1-tP0) of the main reflection time in relation to the calibration time, - allocating the total time delay (tP1-tP0) to a sum of the temporal delays of the THz transmission beam in the wall regions of the measured object (8, 18, 28, 38) and determining geometric layer thicknesses of the measured object, - the main reflection peak at the main reflection time - and measuring peaks (P1, P2, P3, P4. P5, P6) of boundary surfaces oriented perpendicular to the optical axis at partial reflection times (t1, t2, t3, t4, t5, t6), - where geometric layer thicknesses (WTij) of the measured object (8, 18, 28, 38) along the optical axis are determined from temporal differences of the determined partial reflection times (t1, t2, t3, t4, t5, t6) of the measuring peaks (P1, P2, P3, P4. P5, P6) and its refraction index (n0, n1) as air gaps and/or wall regions of the measured object,