The damage mechanism of a nanosecond extreme ultraviolet (EUV) laser with solid targets is complex and involves thermal and nonthermal effects. In this study, the interaction process of a nanosecond 46.9 nm laser with copper was investigated. A Faraday cup was used to measure the electron signals induced by the laser irradiation. The photo-ionization and thermal effects in the interaction process are discussed according to the results.