Abstract: A portable electronic apparatus includes a box type housing made of synthetic resin and having a top wall in which an opening is formed. The housing houses a heat radiating circuit component therein which faces the opening of the top wall of the housing. A keyboard device is provided at the housing in such a manner as to close the opening of the top wall. The keyboard device has a bottom surface, covered by a metal plate, which faces the circuit component. A heat sink is provided between the circuit component and the metal plate. A metal shield is provided between the metal plate and the heat sink. The heat sink includes a bag formed of a flexible film and a liquid refrigerant with which the bag is filled. The bag is in contact with both the circuit component and the metal shield, and can thus absorb heat from the circuit component and transmit the heat to the metal plate.