The present invention relates to a device for dispensing a product for dyeing and/or lightening keratin fibres constituted of a container comprising: i) at least two compartments a and b separate from one another, the compartment a comprising a composition A comprising at least one alkaline agent and optionally at least one dyeing agent, the compartment b comprising an oxidizing composition B comprising at least one chemical oxidizing agent, one and/or the other of the compositions of the two compartments comprising at least one surfactant; ii) a dispensing means equipped with at least one dispensing orifice, in communication with the compartments a and b, making it possible to simultaneously deliver the compositions A and B, the total content of surfactants in the whole of the compositions A and B being greater than or equal to 7% by weight relative to the total weight of A+B. It also relates to a process for dyeing human keratin fibres using said device, and also to a kit comprising said device and a compos
