To supply feeding speeds and regenerative signal output level values of respective frames stored in a storage means to a reproducing output inspection of magnetic information in a camera manufacturing process and to simplify the reproducing output inspection.

This method is provided with a magnetic head 1 reproducing the magnetic information recorded on respective frames of a film, first detection means 5, 6, 9 detecting the feeding speeds answering to respective frames of the film, a second detection means 9 detecting the regenerative signal output level values answering to the frames measured with the feeding speeds by driving the magnetic head and the storage means 7 storing the feeding speeds and the regenerative signal output levels values of respective frames detected by the first, second detection means.