NOVELTY - Recovering phosphorus resources from organic waste such as organic sludge (1) by biologically oxidizing the sludge with oxygen-containing-gas (3), raising temperature of waste to 30 degreesC or more, mineralizing sludge with organic substance, dehydrating concentration sludge, adding magnesium ion source to supernatant liquid, precipitating magnesium-ammonium- phosphate and recovering the precipitate, is new.    USE - For recovering phosphorus resources from organic waste and for manufacturing compost containing high phosphorus content (claimed), useful as fertilizer in agriculture.    ADVANTAGE - The method enables effective biodegradation of organic waste and enables hygienic and safe production of compost. The compost manufacture by the process is used as fertilizer for agriculture. The method enables increased production of compost containing magnesium-ammonium-phosphate and conserves energy. The method is simple and economical.    DETAILED DESCRIPTION - Recovering phosphorus resources from organic waste such as organic sludge (1), comprising:    (a) supplying the organic waste into a stirring tank (2);    (b) biologically oxidizing the sludge with oxygen-containing-gas (3);    (c) raising the temperature of waste to 30 degreesC or more;    (d) mineralizing sludge with organic substance;    (e) dehydrating concentration sludge with a sludge dehydrator (5);    (f) adding magnesium ion source (10) to supernatant liquid;    (g) precipitating magnesium-ammonium-phosphate; and    (h) recovering the precipitate.    INDEPENDENT CLAIMS are also included for the following:    (1) manufacture of compost containing high phosphorus content by the novel method;    (2) apparatus for recovering phosphorus resources from organic waste, which comprises a multi-stage aeration-stirring tank for biologically oxidizing the sludge, sludge concentrating unit for concentrating and dehydrating oxidized sludge into dehydrated cake (7), feed pipe for supplying magnesium ion sources and crystallization tank for preparing compost containing magnesium-ammonium-phosphate (8); and    (3) apparatus for manufacturing compost containing high phosphorus content from organic waste.    DESCRIPTION OF DRAWING(S) - The drawing shows the block diagram of apparatus for recovering phosphorus resource and manufacturing phosphorus containing compost. (Drawing contains non-English language text).    Organic sludge (1)    Stirring tank (2)    Oxygen-containing-gas (3)    Sludge dehydrator (5)    Dehydrated cake (7)    Compost containing magnesium-ammonium- phosphate (8)    Magnesium ion source (10).