A 32-year-old woman carried a copper intrauterine contraceptive device (IUCD) or intrauterine pessar (IAP) for more than 5 years. She had acyclic menstrual bleedings and underwent a corpus abrasio after explantation of IUCD. The histological study of paraffin sections showed an actinomycotic endometritis with brown to black deposits in or around typical actinomyces druses, but there was no carcinoma. The electron microscopic study of these accumulations by electron energy loss spectroscopy (EELS) in TEM demonstrated copper deposits in the shell and matrix of these druses as well as inside the bacteria. With scanning electron microscopy (SEM) and Energy Dispersive X-Ray Analysis (EDX), the electron-dense accumulations revealed high signals for copper and sulfur, but also of phosphorus and oxygen in a lower extent. This copper accumulation is discussed as an active uptake and concentration by these actinomyces bacteria.