Abstract: An aluminum-copper (Al-Cu) thin film reference material for copper content, intended for the calibration of X-ray energy/wave spectrometers, was developed in this study. The uniformity and stability of the developed Al-Cu thin film reference material were evaluated using an electronic probe. An inductively coupled plasma emission spectrometer (ICP-OES) was employed to determine the copper content (wt%) of the reference material. The sources of uncertainty for the copper content in the Al-Cu film standard with a nominal value of 49.5% were examined, and the uncertainty of the reference material was evaluated. The findings indicate that the reference material displays good uniformity and stability. The copper content standard value of the reference material was found to be 49.46 wt%, with an extended uncertainty of 0.98 wt% (k=2). The developed Al-Cu thin film copper content reference material for X-ray energy/wave spectrometer calibration meets the calibration requirements for quantitative analyses conducted with X-ray energy/wave spectrometers. It fills a domestic gap in reference materials for X-ray energy/wave spectrometer calibration and provides a measurement assurance and technical support for the quantitative analysis of copper content in China's scientific research industry.