A microscopic apparatus and an observing method can obtain information of a super-resolved image of an object under observation with a high SN ratio. Therefore, the microscopic apparatus including an illuminating optical system that illuminates a specimen plane of a sample with line-shaped illuminating light, a modulating unit that spatially modulates the illuminating light in a lengthwise direction, an image-forming optical system that forms an image of light from the specimen plane illuminated with the spatially modulated illuminating light, and a detector that detects light from the specimen plane. Accordingly, a confocal effect is obtained with respect to an unstructuring direction of an illuminated area. The essential contrast of the structured illumination of the illuminated area is enhanced by the confocal effect, and thus the modulated image of the illuminated area is detected with a high SN ratio.