In the past years, we developed a new hybrid Monte Carlo (HMC) micromagnetic (MuMag) method that is capable to calculate the magnetic properties at finite temperature. Recently, we have tested more basic characteristics of the HMC MuMag method; furthermore, the HMC MuMag method has been applied to solve the $M$ – $H$ loops and magnetic domains in the polycrystalline soft and hard magnetic materials, from low temperature up to the Curie temperature. The transient properties of the thin-film media responding to the femtosecond laser can also be studied by the HMC MuMag. Above all, the HMC MuMag has an outstanding performance in terms of computational speed, and it is much faster than the MuMag using the Landau–Lifshitz equations with the same number of MuMag cells; thus, the 3-D domains with a larger scale can also be calculated by the finite difference method-fast Fourier transform type of MuMags using the HMC method.