Abstract: A portable electronic device includes a carrier unit and an image-capturing unit. The carrier unit includes a carrier body. The image-capturing unit includes a rotatable element rotatably disposed on the carrier body, two image-capturing modules embedded in the rotatable element, and a weight element disposed inside the rotatable element. The rotatable element has a first geometric center point concurrently passed by a first horizontal line and a vertical line, each image-capturing module has a second geometric center point itself passed by the first horizontal line, the weight element has a third geometric center point passed by a second horizontal line and the vertical line, and the first horizontal line and the second horizontal line are horizontal to each other. Therefore, because the two image-capturing modules are always held in a horizontal state, the portable electronic device can capture high quality 3D images at any usage angle.