A preconcentration-atomic absorption spectrophotometry (AAS) analysis has been established for the measurement of a micro amount of copper in a deposit. The preconcentration is carried out using a column packed with glass beads coated with 3% 4, 4, 4-trifluoro-1-phenyl butane-1, 3-dione (BFA) as a chelating agent. Soluble fraction of the deposit which contains a micro amount of copper (about 1-5 ppb) is passed through the column at a neutral pH range, and the copper is found to be retained quantitatively by the column as a BFA chelate. After the chelate is dissolved in a definite volume of methyl isobutyl ketone (MIBK), copper is measured immediately by flame AAS. As ascertained by recovery test for copper added previously to the sample, no matrix effect of the sample was observed. Average recovery amounted to 96%, and the coefficient of variation was about 8%. Moreover, sensitivity for copper in AAS increased by the addition of excess BFA to the sample.