The present invention provides a dual-beam apparatus which employs the dark-field e-beam inspection method to inspect small particles on a surface of a sample such as wafer and mask with high throughput. The dual beam apparatus comprises two single-beam dark-field units placed in a same vacuum chamber and in two different orientations. The two single-beam dark-field units can perform the particle inspection separately or almost simultaneously by means of the alternately-scanning way. The invention also proposes a triple-beam apparatus for both inspecting and reviewing particles on a sample surface within the same vacuum chamber. The triple-beam apparatus comprises one foregoing dual-beam apparatus performing the particle inspection and one high-resolution SEM performing the particle review.