Adjusting instrument for a mirror, comprising: a first part 2, a second part 3, wherein the first and second parts 2,3 are pivotable relative to each other, wherein the first part 2 is bearing-mounted via a first bearing 4 about a first pivoting axis 6, and wherein the first part 2 together with the first bearing 4 is bearing-mounted directly or indirectly via a second bearing 5 to the second part 3 about a second pivoting axis 7, which is substantially transverse to the first pivoting axis 6, wherein the first bearing comprises a bar spring 8, which bar spring 8 is biased in a bias direction V+ which is substantially transverse to an adjustment plane Vs formed by the first and second pivoting axes 6,7, which bar spring 8 provides that the two parts 2,3 are pressed against each other under bias substantially transversely to the adjustment plane Vs.