Furniture item comprising a compartment, a sliding leaf {22, 24) to close/uncover the compartment, a mechanism mounted inside the compartment to support the leaf during a horizontal movement in order to uncover the compartment, wherein the mechanism comprises a first arm (44, 54) which is mounted inside the compartment, for supporting the leaf during a horizontal movement in order to uncover the compartment, and hinged to the compartment about - in use - a first vertical axis; a second arm (46, 56), which is adapted to be parallel to the sliding direction of the leaf when the leaf is moved to uncover the compartment, has the free end facing the opening direction of the leaf, and at said free end there is mounted a wheel (48, 58) with a pivoting axis parallel to the first and second axes (X I, X2J, the wheel (48, 58) being able to slide inside a complementary guide mounted on the inner side of the leaf, characterized in that the arms (44, 54) are mounted so that the rotation of the second arm (46, 56) with respect to the first arm {44, 54) varies the position of the wheel (48, 58} when the leaf moves, the wheel (48, 58) thereby assuming two different positions relative to the open/closed position of the leaf, and at the end of the stroke of horizontal sliding for the leaf, the first arm is approximately orthogonal to the plane of the leaf (22, 24) and the second arm (46, 56) is substantially orthogonal to the first arm {44, 54) thereby forming at this point an L-shaped arm. a compartment, a sliding leaf {22, 24) to close/uncover the compartment, a mechanism mounted inside the compartment to support the leaf during a horizontal movement in order to uncover the compartment, wherein the mechanism comprises a first arm (44, 54) which is mounted inside the compartment, for supporting the leaf during a horizontal movement in order to uncover the compartment, and hinged to the compartment about - in use - a first vertical axis; a second arm (46, 56), which is adapted to be parallel to the sliding direction of the leaf when the leaf is moved to uncover the compartment, has the free end facing the opening direction of the leaf, and at said free end there is mounted a wheel (48, 58) with a pivoting axis parallel to the first and second axes (X I, X2J, a first arm (44, 54) which is mounted inside the compartment, for supporting the leaf during a horizontal movement in order to uncover the compartment, and hinged to the compartment about - in use - a first vertical axis; mounted inside the compartment, for supporting the leaf during a horizontal movement in order to uncover the compartment, and hinged to the compartment about - in use - a first vertical axis; a second arm (46, 56), which is adapted to be parallel to the sliding direction of the leaf when the leaf is moved to uncover the compartment, has the free end facing the opening direction of the leaf, and at said free end there is mounted a wheel (48, 58) with a pivoting axis parallel to the first and second axes (X I, X2J, is adapted to be parallel to the sliding direction of the leaf when the leaf is moved to uncover the compartment, has the free end facing the opening direction of the leaf, and at said free end there is mounted a wheel (48, 58) with a pivoting axis parallel to the first and second axes (X I, X2J, the wheel (48, 58) being able to slide inside a complementary guide mounted on the inner side of the leaf, characterized in that the arms (44, 54) are mounted so that the rotation of the second arm (46, 56) with respect to the first arm {44, 54) varies the position of the wheel (48, 58} when the leaf moves, the wheel (48, 58) thereby assuming two different positions relative to the open/closed position of the leaf, and at the end of the stroke of horizontal sliding for the leaf, the first arm is approximately orthogonal to the plane of the leaf (22, 24) and the second arm (46, 56) is substantially orthogonal to the first arm {44, 54) thereby forming at this point an L-shaped arm.