Exploiting the tunable energy and polarization, coherence, and pulsed nature of synchrotron X-rays, we develop methods for element-selective observation of the electronic states of magnetic materials using XMCD and resonant X-ray scattering. Our main research topics are magnetic imaging with a soft X-ray microscope, the observation of magnons by time-resolved XMCD imaging, and the observation of multipole orders in antiferromagnets. In imaging research, we have installed a soft X-ray microscope equipped with a four-pole electromagnet at NanoTerasu (Fig. (a)), establishing an environment for real-space observation of magnetic structures by coherent diffraction imaging under magnetic fields applied in arbitrary directions. Using this instrument, we visualize long-period magnetic structures in magnetic materials in real space (Fig. (b)). We have also achieved the world's first visualization of the amplitude and helical phase distribution of soft X-ray vortex beams by inline holography, and extended this approach to quantitatively evaluate the topological charge from the phase distribution. By combining these techniques with measurement informatics, we aim at high-precision visualization of a wide variety of magnetic structures, including topological ones. In dynamics research, we used time-resolved XMCD imaging to observe, in real time on a time scale of about 100 ps, magnons excited in a magnetic thin film by GHz microwaves (Fig. (c)). Bayesian analysis of the spectra further allowed us to quantitatively evaluate the contributions of spin and orbital angular momenta to the magnetization precession. This technique is expected to be applied to operando measurements of spintronic devices and to the physics of orbital angular momentum. In multipole-order research, we focus on the fact that finite signals can appear in XMCD and resonant X-ray scattering even in antiferromagnets and altermagnets without net magnetization, depending on the symmetry of the crystal structure and magnetic order. In an altermagnet, using a symmetry-selective geometry in which the X-ray propagation direction is orthogonal to the weak ferromagnetic moment, we isolated an altermagnetic XMCD signal that cannot be explained by weak ferromagnetism, and demonstrated that states with different magnetic symmetries can be reversibly switched by an in-plane magnetic field. Multiplet calculations reveal that this signal originates from an anisotropic magnetic dipole that appears in the core-excited states. We have also theoretically shown the conditions under which XMCD emerges in collinear altermagnets under a trigonal crystal field, as well as the contribution of magnetic octupole order to XLD.