Abstract: The invention refers to a measuring head for use in radiant energy flash measuring of the thermal diffusivity of heterogeneous samples (S) under employment of a probe beam (B) generated by a radiant energy generating means and a detector means for detecting a temperature rise of the sample (S), comprising a sample holder means (SH) for receiving the sample (S). The technical problem to be solved is to provide a measuring head offering the opportunity to align the sample (S) with the probe beam (B) in order to carry out local measurements of the thermal diffusivity in the axial direction of the sample (S) or to deposite the energy shot on the most suitable area of the sample (S), dependently on the given sample features. Therefore, according to the present invention it is proposed to arrange the sample holder means (SH) movable in at least one direction (X, Y) perpendicular to the optical axis (AB) of the probe beam (B).