The absorption of circularly polarized x-rays in iron was studied using synchrotron radiation. The results show a spin-dependent absorption in the K-edge region of iron, with a spin-dependent contribution of (1.7±0.4)×10⁻³. This spin-dependent absorption is attributed to the difference in spin densities of unoccupied bands. The study used circularly polarized synchrotron radiation from the DORIS storage ring at DESY. The spin-dependent absorption was measured by comparing the transmission of x-rays with spins parallel and antiparallel to the magnetic d-electrons. The results show a significant spin dependence of the photoabsorption in iron, with a maximum of +5.1×10⁻³ at 2 eV above the Fermi level and a minimum of -1.8×10⁻³ at 7 eV. The spin-dependent absorption was also observed in the extended x-ray absorption fine structure (EXAFS) region, with a statistically significant minimum in the spin-dependent transmission of (5±1)×10⁻⁴. The results suggest that the majority-spin band is located at 2 eV above the absorption edge, while the minority-spin band is at 7 eV. The calculated spin densities of the empty states agree with the experimental results, showing a majority-spin band at 2 eV and a minority-spin band at 7 eV. The study demonstrates that spin-dependent x-ray absorption measurements in the near K-edge region of ferromagnets are a new experimental method to measure differences of the spin densities of empty bands near the Fermi level. The experimental procedure is relatively simple and not masked by surface effects, and covers a larger energy range compared to the equivalent inverse photoelectron spectroscopy. The results also show that spin-dependent EXAFS may become a new method for studying the magnetic structure of the neighborhood of the absorber atom. The study is applicable to all ferromagnetic or ferrimagnetic materials, intermetallic compounds, and alloys which can be produced as foils with a thickness of some mg/cm². The results may be important in two aspects: first, the demonstration of a new experimental method to measure spin densities of empty bands near the Fermi level, and second, the observation of spin-dependent EXAFS at the K edge of iron.The absorption of circularly polarized x-rays in iron was studied using synchrotron radiation. The results show a spin-dependent absorption in the K-edge region of iron, with a spin-dependent contribution of (1.7±0.4)×10⁻³. This spin-dependent absorption is attributed to the difference in spin densities of unoccupied bands. The study used circularly polarized synchrotron radiation from the DORIS storage ring at DESY. The spin-dependent absorption was measured by comparing the transmission of x-rays with spins parallel and antiparallel to the magnetic d-electrons. The results show a significant spin dependence of the photoabsorption in iron, with a maximum of +5.1×10⁻³ at 2 eV above the Fermi level and a minimum of -1.8×10⁻³ at 7 eV. The spin-dependent absorption was also observed in the extended x-ray absorption fine structure (EXAFS) region, with a statistically significant minimum in the spin-dependent transmission of (5±1)×10⁻⁴. The results suggest that the majority-spin band is located at 2 eV above the absorption edge, while the minority-spin band is at 7 eV. The calculated spin densities of the empty states agree with the experimental results, showing a majority-spin band at 2 eV and a minority-spin band at 7 eV. The study demonstrates that spin-dependent x-ray absorption measurements in the near K-edge region of ferromagnets are a new experimental method to measure differences of the spin densities of empty bands near the Fermi level. The experimental procedure is relatively simple and not masked by surface effects, and covers a larger energy range compared to the equivalent inverse photoelectron spectroscopy. The results also show that spin-dependent EXAFS may become a new method for studying the magnetic structure of the neighborhood of the absorber atom. The study is applicable to all ferromagnetic or ferrimagnetic materials, intermetallic compounds, and alloys which can be produced as foils with a thickness of some mg/cm². The results may be important in two aspects: first, the demonstration of a new experimental method to measure spin densities of empty bands near the Fermi level, and second, the observation of spin-dependent EXAFS at the K edge of iron.