A dimensionally stable synthetic internal support conveyor belt which comprises (a) at least one homogeneous, flat tape of a molecularly oriented plastic with a modulus of elasticity of 15,000 to 25,000 kp/cm.sup.2. This tape has a fixed profile on both of its large area surfaces and includes reinforcement ribs arranged with their components extending predominantly in the longitudinal direction of the tape. Binding layers are composed of an elastic material with a modulus of elasticity of 800 to 1,000 kp/cm.sup.2 and interlock with the profile on both sides of the tape. Each of the binding layers may be covered with a synthetic fabric. Each of the two binding layers with each of the two synthetic fabrics may be covered with a cover plate of elastomers or thermoplastics.