To provide a piercing rolling method of a metallic tube.

When the opening degree of main rolls is expressed by Rg, the opening degree of guide members by Gg, the outside diameter of a solid round billet by Bd, the effective length of a plug by Ph and the max. outside diameter by Pd, piercing is executed provided that the next equations are satisfied: 0.5×Bd≤Rg≤0.9×Bd, 1.05×Rg≤Gg≤0.95×Bd, 1.5×Pd≤Ph≤6×Pd. In this way, a hollow tube stock whose thickness deviation is smaller, which has not inside flaws and whose outside diameter is ≤0.95 times the outside diameter of the round billet of the base stock.