The present invention relates to an iron-base powder for a powder core, wherein when cross-sections of at least 50 iron-base powders are observed and a crystal grain size distribution containing at least a maximum crystal grain size is determined by measuring a crystal grain size of each iron-base powder, 70% or more of the measured crystal grains are a crystal grain having a crystal grain size of 50 μm or more. According to the iron-base powder of the invention, a coercivity of the powder core can be made small and a hysteresis loss can be reduced.