To obtain an antimicrobial polyacetal molding product that can manifest excellent antifungal and antibacterial properties and is useful as parts of a variety of equipment and instrument in the fields of electric and electronic appliances and cars by restricting the number of vial cells of Escherichia coli on the surface lower than a specific value.

The number of surface vial cells of Escherichia coli is maintained lower than 50/cm2 on the polyacetal resin. For example, (A) 100 pts.wt. of polyacetal rein is mixed with (B) 0.01-2 pts.wt. of a hindered amine as bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate or 4-benzoyloxy-2,2,6,6- tetramethylpiperazine and the resin composition is molded to the objective molding products without adverse effect on the mechanical properties and thermal stability of the component A.