An adsorbent for regenerator systems, to a heat utilization system and a regenerator system that comprise the adsorbent, and to a ferroaluminophosphate and a method for production thereof. More precisely, the invention relates to an adsorbent favorable for regenerator systems, which efficiently utilizes the heat source obtainable from cars and the like to thereby realize efficient regenerator systems, to a regenerator system that comprises the adsorbent, to a ferroaluminophosphate to be the adsorbent favorable for regenerator systems, and to a method for production thereof.