Hi Lemoine,
Yes??testing laboratory which is located in France should have COFRAC accreditation (Check whether testing laboratory have ISO 17025 or not).
An ?accredited testing laboratory? is laboratory which is accredited by national accreditation authorities where laboratory is located (i.e. SCC in Canada, UKAS in UK, COFRAC in France). In general word, it is approved by national accreditation authorities to carry out particular function (testing, calibration etc) for any device, instrument, equipment, product etc. These national authorities inspects the testing laboratories according to particular international standard i.e. ISO - 17025 for Testing/Calibration Laboratories, ISO 17020 for Inspection Bodies, and after inspection they give them certificate for that ISO. You must need to carry out technical tests from such laboratory to show conformity for CE marking of medical device.
Cheers,