To provide a foaming styrenic resin particle causing very little detachment of a coating agent in the course of feeding into a pre-foaming machine, a silo or a foaming molding machine, and also causing very little adhesion of a coating agent to the inner wall surface of a particle flowing pipe.

A liquid polyhydric alcohol is coated twice at ambient temperature, while fatty acid monoglyceride and a metal salt of a fatty acid are added and coated after the first coating of the polyhydric alcohol, followed by the second coating of the polyhydric alcohol, to provide the foaming styrenic resin particles coated with 0.02-0.3 pts.wt. of the polyhydric alcohol, 0.01-0.3 pts.wt. of the fatty acid monoglyceride, and 0.03-0.3 pts.wt. of the metal salt of the fatty acid, based on 100 pts.wt. of the foaming styrenic resin particle.