A portable electronic apparatus includes a display panel, an outer casing, a backlight module disposed between the display panel and the outer casing, and an outer frame disposed on the display panel for fixing the display panel and the backlight module with the outer casing. A frame structure is formed on the outer casing and has a pillar and a slot. The backlight module includes a light guide plate, plural light emitting units disposed at a side of the light guide plate, and a cover member. The cover member is disposed on the outer casing corresponding to the light emitting units and has a bending hook portion and a holding board portion for holding the display panel. The holding board portion has a hole for engaging with the pillar when the bending hook portion hooks the slot, so that the cover member can cover the light emitting units.