Radiation unit of electronic device and electronic device using same

A cooling unit for electronic devices, comprising:

• a partition board disposed on one of a plurality of surfaces of an electronic device, the partition board separating an inner side and an outer side of the electronic device;
• a heat exchanger disposed on the outer side, the heat exchanger exchanging heat generated by the electronic device with outside air;
• and
• a blower disposed on the outer side, wherein
• the partition board has a first vent and a second vent,
• the heat exchanger includes hot-air passage bodies and air pathways, the hot-air passage bodies including a plurality of air passages arranged side by side at predetermined intervals in such a manner as to connect the first vent and the second vent on the outer side, the air pathways being formed between adjacent ones of the air passages so as to allow the outside air to pass through, and
• the blower blows air of the inner side from the first vent to the second vent through the hot-air passage bodies.