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, which is transferred from the heat absorbing section, 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 while allowing the air to pass by a predetermined element. The cooling unit further includes: a filter which is detachably installed between the blowing opening and the ventilation area to remove foreign substances present in the air blown to the ventilation area from the blowing opening; and a filter fixing section which is integral with the filter and extended astride the element, while allowing the filter to be removably fixed.