A surface of a sample is observed by acquiring an image of the surface of the sample. An electron beam I irradiated onto the surface of the sample in which wiring including an insulation material and an electrically conductive material is formed. Electrons that acquired structure information regarding a structure of the surface of the sample are detected. An image of the surface of the sample is acquired by a result of the detection of electrons. The surface of the sample is observed using the acquired image of the surface of the sample. The electron beam is irradiated onto the surface of the sample in a state where a brightness of the insulation material and a brightness of the electrically conductive material in the image of the surface of the sample are set equal to each other.