Abstract: Provided is a powder which has a high saturation magnetic flux density and excellent flame retardancy. This powder is a flame retardant powder for a magnetic member, and includes a plurality of flaky particles. These particles are composed of an Fe—Si-based alloy containing 7% by mass or more and 12% by mass or less of Si. The content of Si in terms of percentage by mass, P(Si), in this alloy and the flame retardancy parameter PNF satisfy the following mathematical formulae (I) and (II): (?0.97×P(Si)+13.0)<PNF?10 (I), PNF=D50×TD/? (II), wherein, D50 represents the median diameter of the powder, TD represents the tap density of the powder, and ? represents the true density of the powder.