A charging device for electrically charging a member to be charged includes charging particles including electroconductive particles having particles diameters in the range of 10 nm-10 .mu.m; and a charging particles carrying member, which has a nip with the member to be charged forming a nip with said member to be charged, for carrying the charging particle to the nip; wherein said charging particles have resistances in the range of 10.sup.-1 -10.sup.12 .OMEGA.cm; wherein (an amount, per unit area, of said charging particles carried by said charging particles carrying member)/(an average roughness Ra of a surface of said charging particles carrying member) is in the range of 0.005-1 mg/cm.sup.2 /.mu.m.