The invention relates to a mattress (10) comprising: at least one first mattress element (30) having a first contact surface (34) and an oppositely arranged first outer surface (32), said first outer surface (32) being configured as a first
lying surface for a user; and at least one second mattress element (40) having a second contact surface (44) and an oppositely arranged second outer surface (42), the second outer surface (42) being configured as a second
lying surface of the user; the first and second mattress elements (30, 40) are at least partially in contact with each other in a superimposed manner by means of their contact surfaces (34, 44). The mattress (10) is provided with a head support region (20a, 20b) for supporting the head, a neck support region (22a, 22b) for supporting the neck, a
shoulder support region (24a, 24b) for supporting the shoulder, a
lumbar support region (26a, 26b) for supporting at least part of the spine, and a
pelvis support region (28a, 28b) for supporting the
pelvis. The first outer surface (32) of the first mattress element (30) and the second outer surface (42) of the second mattress element (40) are each provided with a contour structure (50, 46) such that the two mattress elements differ from each other in compression
hardness and / or
hardness levels. The thickness (D) of the mattress (10) is at least 24 cm. A contour structure (50) provided at the second outer surface (42) of the second mattress element (40) has a plurality of grooves (52a), preferably three, in the at least one pelvic support region (28a, 28b), which grooves have a triangular cross-section and whose cross-sectional areas differ at least partially from one another.