Is a C# static method's variable initialised every time the method is called?

In the example below, will a new StringBuilder(255) be created every time the static Flog.Log() function is called, or will it only be created the first time the method is called?

public class Flog { public static void Log(FlogType flogType, string msg, params System.Object[] p) { StringBuilder sb = new StringBuilder(255); sb.Length = 0; sb.AppendFormat(msg, p); Log(flogType, sb.ToString()); }
}