Heat exchanger and refrigeration cycle apparatus

A heat exchanger comprising:

• a plurality of fins being spaced apart from one another in a first direction;
• and
• a plurality of heat transfer tubes penetrating through the plurality of fins, the plurality of heat transfer tubes being spaced apart from one another in a second direction crossing the first direction,
• wherein
• each of the plurality of fins includes
• a fin base surface that is flat, and
• a plurality of fin projections, and
• the plurality of fin projections include
• inner fin projections provided to separately surround each of the plurality of heat transfer tubes, the inner fin projections protruding in the first direction from the fin base surface, and
• outer fin projections provided to separately surround each of the inner fin projections, the outer fin projections protruding in a same direction with the inner fin projections from the fin base surface, and
• the inner fin projections and the outer fin projections are adjacent to each other without gaps.