PER CURIAM.
Petitioner seeks permission to file a petition for writ of mandamus in forma pauperis. Such leave will not be granted unless there is some merit in the petition. 28 U.S.C.A. § 832; Boggan v. Provident Life Accident Ins. Co., 5 Cir., 79 F.2d 721; De Groot v. U.S., 9 Cir., 88 F.2d 624. Petitioner seeks a writ directing a District Judge to set aside his order denying petitioner leave to prosecute an appeal in forma pauperis from an order of the District Court denying petitioner's writ of habeas corpus. A petition for leave to prosecute an appeal in forma pauperis is granted only when there is some merit in the appeal. Boggan v. Provident Life Accident Ins. Co., supra; De Groot v. U.S., supra. This is a question to be decided by the judge to whom the application is made. The proposed petition shows that the trial judge certified that the appeal was frivolous and denied the application for leave to appeal in forma pauperis. Mandamus can not be used to review this action of the trial court which involves the exercise of discretion and judgment. In re Parsons, 150 U.S. 150, 14 S.Ct. 50, 37 L.Ed. 1034; Hudson v. Parker, 156 U.S. 277, 15 S.Ct. 450, 39 L.Ed. 424; In re Press Printers Publishers, 3 Cir., 12 F.2d 660. As there is no merit in the petition for writ of mandamus leave to file it without prepayment of costs is denied.