The Quality Control working group of RTmfm is composed of 9 members (Members). It develops tools (Quality Control Tools), workflows, and guidelines for regular quality control measurements in light microscopy. The expertise is shared though trainings (Training), videos (Video tutorials) and protocols papers published in scientific journals (Articles). The group owns a “Metrology suitcase” that is available to use with all the necessary material for starting quality control in light microscopy (Metrology case). The group is highly implicated in the international scene of quality control with its participation to QUAREP-LiMi. The last years, the group is also establishing a dialogue with the main microscope constructors for an harmonization of the quality control procedures and to facilitate the communication between the service technician and the facility staff or laboratory researcher.