An electronic device is provided. The electronic device includes a transparent member, a display positioned under a transparent member that includes a plurality of pixels, an image sensor positioned under some areas of the display, a memory, and a processor. The processor obtains a first image at least based on light output through at least some of the plurality of pixels and reflected by an external object coming into contact with the transparent member using the image sensor, performs authentication on the external object at least based on the at least one template using the first image, generates a second image of the external object at least based on the first image when quality of the first image corresponds to a given condition based on a result of the authentication, and performs authentication on the external object at least based on the at least one template using the second image.