The invention provides a method for measuring, with high sensitivity, phosphoethanolamine (PEA) in a sample, the method comprising: (a) a step for removing ammonia and/or phosphoric acid in a sample; (b) a step for adding an enzyme to the sample obtained in step (a) to produce ammonia and/or phosphoric acid from PEA contained in the sample; (c) a step for adding a composition for detecting ammonia and/or a composition for detecting phosphoric acid to the sample obtained in step (b); and (d) a step for detecting ammonia and/or phosphoric acid in the sample obtained in step (c). Also provided are a kit, a program, and a device for executing said method.
