The invention relates to device for measuring the thickness of a transparent sample (2), particularly a glass strip or a glass pane, involving the use of: a first light beam (L1), particularly a first laser beam, which strikes upon the front surface (8) of the sample (2) at a first angle of incidence (.alpha.1); a second light beam (L2), particularly a second laser beam, which strikes upon the front surface (8) of the sample (2) at a second angle of incidence (.alpha.2), the first angle of incidence (.alpha.1) and the second angle of incidence (.alpha.2) being different, and; at least one detector (11, 12) for detecting the light beams (L1', L1'', L2', L2'') of the first and second incident light beams (L1, L2) reflected by the sample, and for determining the position thereof. In order to also be able to carry out a correction for curvature, at least one incident light beam (L3), which is essentially parallel to the first or second light beam (L1, L2), is oriented toward the front surface (8) of the sample (2), and at least one detector (11) is provided for detecting a light beam (L3') of the parallel light beam (L3) reflected by the sample (2) and for determining the position thereof. The invention also relates to a corresponding method.