To provide a metallic contamination preventing system in a clean room, which effectively removes metallic particles attached to a clean suit in moving to another room to prevent diffusion of metallic contamination.

This metallic contamination preventing system 10 disposed in an inlet/outlet booth 60 where a worker passes in entering and leaving a work room in the clean room, has a pair of adhesive sheets 12 disposed while adhesive faces are opposed to each other to hold a body of the worker 40 at a metallic particle removing position, and tension rollers 20 for pressing the adhesive sheets 12 to the body of the worker 40 at the metallic particle removing position. Further, this metallic contamination preventing system 10 preferably includes rollers 14 for feeding out the adhesive sheets 12 to the metallic particle removing position, and take-up rollers 16 for taking up the adhesive sheets 12 used in the metallic particle removing position.