A device is provided for dispensing seeds singly. The device includes a drum, a dispensing disc, a vacuum chamber and a seal of the vacuum chamber, between the drum and the disc. The seal includes a friction insert mounted so as to be immobile in rotation relative to the drum against the periphery of the disc and an elastic seal mounted so as to be immobile in rotation between the drum and the friction insert. The elastic seal maintains the friction insert in a position of leaning against the disc.