The present invention provides a light beam measuring instrument that can securely receive light reflected by a sample. The light beam measuring instrument 1 includes an optical axis tilting mechanism 13 that includes a first tilting mechanism 131 and a second tilting mechanism 132. From the optical axis A1 of irradiation light beam emitted from a light beam source 112, the first tilting mechanism 131 tilts the optical axis A1 about the first tilting axis T1. The second tilting mechanism 132 tilts the optical axis A1 about the second tilting axis T2. The light beam measuring instrument 1 can receive the light reflected by the semiconductor chip C by means of operation of the optical axis tilting mechanism 13 even if the light reflected by the semiconductor chip C is tilted. Accordingly, this apparatus can securely perform measurement or inspection using the light beam.