A charged-particle-beam device used for measuring the dimensions, etc., of fine circuit patterns in a semiconductor manufacturing process, wherein corrections are made in the defocusing and astigmatism generated during changes in the operating conditions of a Wien filter acting as a deflector of secondary signals such as secondary electrons, and the display dimensions of obtained images are kept constant. In the charged-particle-beam device, the Wien filter (23) is arranged between a detector and a lens (11) arranged on the test-sample side among two stages of lenses for converging a charged-particle beam, and a computing device (93) is provided for the interlocked control of the Wien filter (23) and a lens (12) arranged on the charged-particle-source side among the two stages of lenses.