Scanning electron microscope and sample observation method by means of scanning electron microscope

The present invention realizes a scanning electron microscope that is capable of removing electrostatic charge build-up on the lateral wall of a deep hole/groove and that inspects and measures the bottom portion of the deep hole/groove with high accuracy. On this account, in the scanning electron microscope which has: an electron source (201) which emits primary electrons; a sample stage (213) on which a sample is placed; a deflector 207 which causes scanning on the sample by the primary electrons; an objective lens (203) which converges the primary electrons onto the sample; and a detector (206) which detects secondary electrons generated as a result of irradiation of the sample with the primary electrons, control is performed such that, during a first period in which the sample is irradiated with the primary electrons, the electric potential applied to the sample stage has a negative polarity with respect to the electric potential applied to the objective lens, whereas during a second period in which the sample is not irradiated with the primary electrons, the electric potential applied to the sample stage has a positive polarity with respect to the electric potential applied to the objective lens.