A cooling unit includes: a heat absorbing section which absorbs heat from a heat-producing element; a heat radiating section which defines a ventilation area and radiates the heat into air passing through the ventilation area; and a fan having a blowing opening and blowing air toward the ventilation area from the blowing opening. The blowing opening and the ventilation area are different in size and/or position in a direction intersecting a flow of the air. The cooling unit further includes a filter installed between the blowing opening and the ventilation area to remove foreign substances in the air blown to the ventilation area. The filter has a wall guiding the air to the ventilation area from the blowing opening by connecting the blowing opening and the ventilation area at a part of a portion that is a difference in size and/or position between the blowing opening and the ventilation area.