To increase design flexibility, improve processability and productivity of a lap portion and so on, and enhance the efficiency and so on in the compression operation by making the turning radius of a rotary scroll different between a low pressure stage and a high pressure stage.

A low pressure scroll unit 4A including a fixed scroll 5A, a rotary scroll 20A and so on, and a high pressure scroll unit 4B including a fixed scroll 5B, a rotary scroll 20B and so on are placed in both sides of a casing 1 in the axial direction. In the casing 1, an electric motor 12 is placed for rotatingly driving the rotary scrolls 20A and 20B via a rotary shaft 15, eccentric cylinders 18A, 18B, rotary bearings 19A, 19B, and so on. The low pressure rotary scroll 20A rotates with a greater turning radius (δa>δb) than the high pressure rotary scroll 20B.