To provide an apparatus and a method for manufacturing a catalytic converter capable of surely and effectively manufacturing the catalytic converter, a gauge assembly for the same, and an assembly machine including the gauge assembly.

The apparatus for manufacturing the catalytic converter 2 wherein a monolith substrate 6 surrounded by a mat material 8 is stored in an outer tube 4 and the outer tube is compressed, includes a preliminary compression means for compressing the monolith substrate surrounded by the mat material and establishing a selective compression sequence, and a compression means for compressing the outer tube on the mat material and the monolith substrate by the selective compression sequence.