To provide a rear bumper structure capable of facilitating get-in/out of a vehicle.

An opening edge part of a diffuser 14 of a rear bumper 13 is integrally formed with a flange 31 extended forward F of a vehicle, and an extension part 41 extended rearward R of the vehicle is integrally formed on an extension line of a lower edge flange part 33. With this structure, the extension part 41 and the lower edge flange part 33 form a step 42 provided with a step margin from a front end of the lower edge flange 33 to a rear end of the extension part 41. A plurality of projecting beads 51 extended in the car cross direction are provided in the top surface of the step 42 so as to form a non-slip part 52.