A charging member comprising: an electro-conductive substrate; and an electro-conductive elastic layer (2; 21, 22) as a surface layer on the substrate, wherein the electro-conductive elastic layer (2; 21, 22) comprises a binder, and retains a bowl-shaped resin particle having an opening, so that the opening of the bowl-shaped resin particle is exposed at a surface of the charging member; the surface of the charging member comprises: a concavity derived from the opening of the bowl-shaped resin particle exposed at the surface, and a protrusion derived from an edge of the opening of the bowl-shaped resin particle exposed at the surface; a part of the surface of the charging member is constituted by the electro-conductive elastic layer (2; 21, 22); and relations represented by the following formulae and are satisfied, 0.2 ≤ S = S 5 − S 1 S 1 ≤ 0.5 0.15 ≤ d = d 5 − d 1 d 1 ≤ 0.5 wherein when the charging member is pressed onto a glass plate so that a load on the glass plate is 100 g (1.000278 N), wherein said glass plate is a glass plate which has a surface accuracy by optical grinding of both sides, and a parallelism within 1 minute, in a contact region R1 comprising at least one contact portion between the charging member and the glass plate in a nip between the charging member and the glass plate, S1 is defined as an average value of contact areas between the charging member and the glass plate in the respective contact portions and d1 is defined as an average value of heights of respective spaces formed between the charging member and the glass plate in the contact region R1; and when the charging member is pressed onto a glass plate so that a load on the glass plate is 500 g (4.903 N), in a contact region R5 comprising at least one contact portion between the charging member and the glass plate in a nip between the charging member and the glass plate, S5 is defined as an average value of contact areas between the charging member and the glass plate in the respective contact portions and d5 is defined as an average value of heights of respective spaces formed between the charging member and the glass plate in the contact region R5. an electro-conductive substrate; and an electro-conductive elastic layer (2; 21, 22) as a surface layer on the substrate, wherein the electro-conductive elastic layer (2; 21, 22) comprises a binder, and retains a bowl-shaped resin particle having an opening, so that the opening of the bowl-shaped resin particle is exposed at a surface of the charging member; a concavity derived from the opening of the bowl-shaped resin particle exposed at the surface, and a protrusion derived from an edge of the opening of the bowl-shaped resin particle exposed at the surface; a part of the surface of the charging member is constituted by the electro-conductive elastic layer (2; 21, 22); and relations represented by the following formulae and are satisfied, 0.2 ≤ S = S 5 − S 1 S 1 ≤ 0.5 0.15 ≤ d = d 5 − d 1 d 1 ≤ 0.5 wherein when the charging member is pressed onto a glass plate so that a load on the glass plate is 100 g (1.000278 N), wherein said glass plate is a glass plate which has a surface accuracy by optical grinding of both sides, and a parallelism within 1 minute, in a contact region R1 comprising at least one contact portion between the charging member and the glass plate in a nip between the charging member and the glass plate, S1 is defined as an average value of contact areas between the charging member and the glass plate in the respective contact portions and d1 is defined as an average value of heights of respective spaces formed between the charging member and the glass plate in the contact region R1; and when the charging member is pressed onto a glass plate so that a load on the glass plate is 500 g (4.903 N), in a contact region R5 comprising at least one contact portion between the charging member and the glass plate in a nip between the charging member and the glass plate, S5 is defined as an average value of contact areas between the charging member and the glass plate in the respective contact portions and d5 is defined as an average value of heights of respective spaces formed between the charging member and the glass plate in the contact region R5. when the charging member is pressed onto a glass plate so that a load on the glass plate is 100 g (1.000278 N), wherein said glass plate is a glass plate which has a surface accuracy by optical grinding of both sides, and a parallelism within 1 minute, in a contact region R1 comprising at least one contact portion between the charging member and the glass plate in a nip between the charging member and the glass plate, S1 is defined as an average value of contact areas between the charging member and the glass plate in the respective contact portions and d1 is defined as an average value of heights of respective spaces formed between the charging member and the glass plate in the contact region R1; and when the charging member is pressed onto a glass plate so that a load on the glass plate is 500 g (4.903 N), in a contact region R5 comprising at least one contact portion between the charging member and the glass plate in a nip between the charging member and the glass plate, S5 is defined as an average value of contact areas between the charging member and the glass plate in the respective contact portions and d5 is defined as an average value of heights of respective spaces formed between the charging member and the glass plate in the contact region R5.