Abstract <p>We aimed to obtain a composite material of apatite and charcoal with excellent adsorption capacity for various substances by heat treating salmon bones. Salmon bone was sintered under air and nitrogen atmospheres, and its characteristics were evaluated. Component and identification analyses were conducted using X-ray fluorescence and powder X-ray diffraction. The analyses confirmed the diffraction pattern of hydroxyapatite in both samples sintered under air and nitrogen atmospheres. Further, the higher the sintering temperature, the higher the crystallinity of the hydroxyapatite. The cumulative pore volume of the salmon bone powder sintered under nitrogen atmosphere was larger than that of the sample sintered under air atmosphere, and the carbon content of the salmon bone powder sintered under nitrogen atmosphere was 6–100 times higher than that of the sample sintered under air atmosphere.</p> Graphical abstract <p></p>