Robotic vacuum cleaner for autonomous cleaning of floor surfaces of a room, comprising - a housing, - a suction fan arranged in the housing for generating a suction air flow, - a dirt container arranged in the housing for receiving dirt particles, - a suction mouth, - a suction channel for fluidically connecting the suction mouth to the suction fan, and - a rotationally drivable main brush arranged on the housing, wherein dirt particles can be picked up from the floor surface by means of the effect of the suction air flow at the suction mouth, and can be conducted to the dirt container by means of the suction channel, wherein the main brush extends transversely to a travel direction of the housing, wherein an auxiliary brush which, viewed counter to the travel direction of the robotic vacuum cleaner, is arranged upstream of the main brush and extends in parallel with the main brush, wherein the auxiliary brush is arranged relative to the main brush in such a way that a horizontal operating plane of the auxiliary brush, to which a brush element of the auxiliary brush extends at the maximum downwards extension thereof, is arranged vertically above a horizontal operating plane of the main brush, to which a brush element of the main brush extends at the maximum downwards extension thereof, so that the operating planes (10, 12) are arranged at a distance from one another, characterised in that an outer diameter of the auxiliary brush is smaller than an outer diameter of the main brush. - a housing, - a suction fan arranged in the housing for generating a suction air flow, - a dirt container arranged in the housing for receiving dirt particles, - a suction mouth, - a suction channel for fluidically connecting the suction mouth to the suction fan, and - a rotationally drivable main brush arranged on the housing, wherein dirt particles can be picked up from the floor surface by means of the effect of the suction air flow at the suction mouth, and can be conducted to the dirt container by means of the suction channel, wherein the main brush extends transversely to a travel direction of the housing, wherein an auxiliary brush which, viewed counter to the travel direction of the robotic vacuum cleaner, is arranged upstream of the main brush and extends in parallel with the main brush, wherein the auxiliary brush is arranged relative to the main brush in such a way that a horizontal operating plane of the auxiliary brush, to which a brush element of the auxiliary brush extends at the maximum downwards extension thereof, is arranged vertically above a horizontal operating plane of the main brush, to which a brush element of the main brush extends at the maximum downwards extension thereof, so that the operating planes (10, 12) are arranged at a distance from one another, characterised in that an outer diameter of the auxiliary brush is smaller than an outer diameter of the main brush. wherein dirt particles can be picked up from the floor surface by means of the effect of the suction air flow at the suction mouth, and can be conducted to the dirt container by means of the suction channel, wherein the main brush extends transversely to a travel direction of the housing, wherein an auxiliary brush which, viewed counter to the travel direction of the robotic vacuum cleaner, is arranged upstream of the main brush and extends in parallel with the main brush, wherein the auxiliary brush is arranged relative to the main brush in such a way that a horizontal operating plane of the auxiliary brush, to which a brush element of the auxiliary brush extends at the maximum downwards extension thereof, is arranged vertically above a horizontal operating plane of the main brush, to which a brush element of the main brush extends at the maximum downwards extension thereof, so that the operating planes (10, 12) are arranged at a distance from one another, characterised in that an outer diameter of the auxiliary brush is smaller than an outer diameter of the main brush.