The invention concerns an ellipsometer comprising: a source (2) capable of emitting a broadband ray (4), a polarizer (10) for producing a polarised incident beam (12) adapted to illuminate a sample (16) according to at least a selected angle; an analyzer (24) providing an output beam (28) in response to said reflected beam (20) and at least a reflecting optical element (14) arranged between the source (2) and the sample (16) and/or between the sample (16) and the sensor, and capable of focusing the incident beam (12) and/or the reflected beam (20) according to a selected spot The ellipsometer further comprises at least a first refracting optical element (22) arranged between the sample (16) and the sensor and/or between the source (2) and the sample (16) to collect and focus said reflected beam and/or said incident beam, thereby enabling to provide at least a refracting element (22) and a reflecting element (14) on either side of the sample (16) and hence to place the source and the sensor on the same side relative to said spot.