Heat exchanger and burner

A heat exchanger comprising a honeycomb structure having ceramics as a main component, the honeycomb structure comprising:

• an outer peripheral wall;
• a first intermediate wall and a second intermediate wall, each including a portion provided on an inner side of the outer peripheral wall;
• a first partition wall provided on an inner side of the first intermediate wall, the first partition wall defining a plurality of cells to form a first flow path;
• a second partition wall provided between the first intermediate wall and the second intermediate wall, the second partition wall defining a plurality of cells to form a second flow path;
• and
• a third partition wall provided between the second intermediate wall and the outer peripheral wall, the third partition wall defining a plurality of cells to form a third flow path,
• wherein the first flow path, the second flow path, and the third flow path are configured to be coaxially positioned.