This scanning electron microscope is provided with: a deceleration means that decelerates an electron beam (5) when the electron beam is passing through an objective lens; and a first detector (8) and a second detector (7) that are disposed between the electron beam and the objective lens and have a sensitive surface having an axially symmetric shape with respect to the optical axis of the electron beam. The first detector is provided at the sample side with respect to the second detector, and exclusively detects the signal electrons having a high energy that have passed through a retarding field energy filter (9A). When the distance between the tip (13) at the sample side of the objective lens and the sensitive surface of the first detector is L1 and the distance between the tip at the sample side of the objective lens and the sensitive surface of the second detector is L2, then L1/L2≦5/9. As a result, when performing low-acceleration observation using a deceleration method by means of a scanning electron microscope, it is possible to detect signal electrons without the effect of shading in a magnification range of a low magnification on the order of hundreds of times to a high magnification of at least 100,000×. Also, it is possible to highly efficiently detect backscattered electrons, of which the amount generated is less than that of secondary electrons.