Container of plastic material having a flattened body and a bottom in the extension of the body having peripheral seat defining a seating plane the contour of which has in the same plane a large dimension A1 and a small dimension A2 that is strictly smaller than the large dimension, and an inner annular cheek substantially perpendicular to the seating plane. The bottom having a concave arch that extends from the seat towards a central zone. A height H of the cheek and a width L of the seating plane are such that 0.5 ≤ L H ≤ 2.5 . A transverse extension A of the seating plane and a transverse extension B of the body, measured near the bottom, are such that A B ≥ 0.85 .