Charging roller, process cartridge, image forming apparatus, and image forming method

A charging roller comprising:

• a conductive shaft;
• an elastic body layer formed on an outer periphery of the conductive shaft;
• and
• a surface layer formed on an outer periphery of the elastic body layer, wherein
• the surface layer contains a binder resin and conductive particles,
• the binder resin contains only a thermoplastic resin,
• the thermoplastic resin has a water contact angle of not less than 40° but less than 180°,
• the conductive particles contain first conductive particles and second conductive particles,
• the first conductive particles are metal oxide particles,
• a content of the first conductive particles in the surface layer is not less than 15.0 parts by mass but not more than 200.0 parts by mass with respect to 100.0 parts by mass of the binder resin, and
• a particle size distribution of the conductive particles has at least one peak within a range of not less than 0.01 μm but not more than 1.00 μm.