The scroll wrap section of an orbitally operating scroll comprises a flat outer circumferential section, a flat inner circumferential section, and a linearly inclined section. During the initial period of compression operation, a very small axial gap is formed between the flat outer circumferential surface of the flat outer circumferential section and the bottom of the other scroll component to allow the air to be reliably contained in the outermost circumferential compression chamber. When the compressor is warmed, the compression heat generated by the air sucked from the suction port causes the inclined section to substantially reduce the axial gap between the inclined section and the bottom of the fixed scroll component and between the inner circumferential flat section and the bottom of the fixed scroll component.