A method of manufacturing a power module substrate having a conductive pattern provided on a surface of a ceramics substrate, the method comprising the steps of: temporarily fixing a base material on a first surface of a brazing sheet by the surface tension of a volatile organic medium before a conductive pattern member is punched out from the base material; punching out the base material and forming the conductive pattern member while the base material is temporarily fixed on the first surface of the brazing sheet by the surface tension of the volatile organic medium, the base material being punched out together with the brazing sheet so that the conductive pattern member and a brazing sheet portion have the same outer shape; fitting the conductive pattern member and the brazing sheet portion into a punching hole formed in the base material, thereby forming a push-back member; arranging a template having a guide hole between the push-back member and the ceramics substrate, the brazing sheet portion, which is temporarily fixed to the conductive pattern member, facing the surface of the ceramics substrate; pressing the conductive pattern member from the punching hole toward the surface of the ceramics substrate to be pulled out of the push-back member; temporarily fixing the second surface of the brazing sheet portion on the surface of the ceramics substrate by the surface tension of the volatile organic medium, which is coated on the second surface of the brazing sheet portion or on the surface of the ceramics substrate; heating the brazing sheet portion and the conductive pattern member so as to volatilize the volatile organic medium; pressing at least the conductive pattern member in its thickness direction; and melting the brazing sheet portion to join the conductive pattern member with the surface of the ceramics substrate. temporarily fixing a base material on a first surface of a brazing sheet by the surface tension of a volatile organic medium before a conductive pattern member is punched out from the base material; punching out the base material and forming the conductive pattern member while the base material is temporarily fixed on the first surface of the brazing sheet by the surface tension of the volatile organic medium, the base material being punched out together with the brazing sheet so that the conductive pattern member and a brazing sheet portion have the same outer shape; fitting the conductive pattern member and the brazing sheet portion into a punching hole formed in the base material, thereby forming a push-back member; arranging a template having a guide hole between the push-back member and the ceramics substrate, the brazing sheet portion, which is temporarily fixed to the conductive pattern member, facing the surface of the ceramics substrate; pressing the conductive pattern member from the punching hole toward the surface of the ceramics substrate to be pulled out of the push-back member; temporarily fixing the second surface of the brazing sheet portion on the surface of the ceramics substrate by the surface tension of the volatile organic medium, which is coated on the second surface of the brazing sheet portion or on the surface of the ceramics substrate; heating the brazing sheet portion and the conductive pattern member so as to volatilize the volatile organic medium; pressing at least the conductive pattern member in its thickness direction; and melting the brazing sheet portion to join the conductive pattern member with the surface of the ceramics substrate.