An electrical device with zooming function includes an image-sensing module, a display unit and a processing unit. The processing unit is electrically connected to the image-sensing module and the display unit respectively. The image-sensing module senses an image. The processing unit includes an image display module, a selecting module and a zooming-control module. The image display module makes the display unit display the sensed image. The selecting module receives a selection signal for selecting a reference point from the image displayed on the display unit. The zooming-control module makes the image-sensing module sense another image, the reference point is in the center of which, by zooming.