An apparatus for measuring a thread includes a holder for detachably holding a tube having a thread formed at an end of the tube. A first optical measuring section having an optical sensor is attached to a manipulator in order to move the measuring section relative to the tube. The optical measuring section is adjustably tiltable about a first adjusting axis relative to a thread axis of the thread. A second optical measuring section having a second optical sensor is arranged at the manipulator, wherein the optical measuring sections collectively form a measuring channel to provide simultaneous measurement of opposite sides of the thread of the tube.