An asymmetrical scroll compressor comprising: a fixed scroll including a first spiral wrap standing up from an end plate of the fixed scroll; and an orbiting scroll including a second spiral wrap standing up from an end plate of the orbiting scroll; wherein the first spiral wrap of the fixed scroll is engaged with the second spiral wrap of the orbiting scroll to define a compression chamber between the fixed scroll and the orbiting scroll, the compression chamber includes a first compression chamber on an outer wrap wall side of the orbiting scroll; and a second compression chamber on an inner wrap wall side of the orbiting scroll, a suction volume of the first compression chamber is more than a suction volume of the second compression chamber, the asymmetrical scroll compressor further comprises at least one injection port through which an intermediate-pressure refrigerant is injected into the first compression chamber and the second compression chamber, the at least one injection port penetrating the end plate of the fixed scroll at a position where the injection port is open to the first compression chamber or the second compression chamber during a compression stroke after a suction refrigerant is introduced and closed, and an amount of the refrigerant injected from the injection port to the first compression chamber is more than an amount of the refrigerant injected from the injection port to the second compression chamber, an oil reservoir in which oil is stored is defined in a sealed container including the fixed scroll and the orbiting scroll, characterised in that a high-pressure area and a back-pressure chamber are defined on a rear surface of the orbiting scroll, an oil supplying passage through which the oil is supplied from the oil reservoir to the compression chamber passes through the back-pressure chamber, the oil supplying passage through which the back-pressure chamber communicates with the first compression chamber and the second compression chamber is provided at the position where the injection port is open to the first compression chamber and the second compression chamber during the compression stroke after the suction refrigerant is introduced and closed, and at least a partial section of an oil supplying section in which the oil supplying passage communicates with the first compression chamber or the second compression chamber overlaps with an opening section in which the injection port is open to the first compression chamber or the second compression chamber. a fixed scroll including a first spiral wrap standing up from an end plate of the fixed scroll; and an orbiting scroll including a second spiral wrap standing up from an end plate of the orbiting scroll; wherein the first spiral wrap of the fixed scroll is engaged with the second spiral wrap of the orbiting scroll to define a compression chamber between the fixed scroll and the orbiting scroll, the compression chamber includes a first compression chamber on an outer wrap wall side of the orbiting scroll; and a second compression chamber on an inner wrap wall side of the orbiting scroll, a suction volume of the first compression chamber is more than a suction volume of the second compression chamber, the asymmetrical scroll compressor further comprises at least one injection port through which an intermediate-pressure refrigerant is injected into the first compression chamber and the second compression chamber, the at least one injection port penetrating the end plate of the fixed scroll at a position where the injection port is open to the first compression chamber or the second compression chamber during a compression stroke after a suction refrigerant is introduced and closed, and an amount of the refrigerant injected from the injection port to the first compression chamber is more than an amount of the refrigerant injected from the injection port to the second compression chamber, an oil reservoir in which oil is stored is defined in a sealed container including the fixed scroll and the orbiting scroll, a high-pressure area and a back-pressure chamber are defined on a rear surface of the orbiting scroll, an oil supplying passage through which the oil is supplied from the oil reservoir to the compression chamber passes through the back-pressure chamber, the oil supplying passage through which the back-pressure chamber communicates with the first compression chamber and the second compression chamber is provided at the position where the injection port is open to the first compression chamber and the second compression chamber during the compression stroke after the suction refrigerant is introduced and closed, and at least a partial section of an oil supplying section in which the oil supplying passage communicates with the first compression chamber or the second compression chamber overlaps with an opening section in which the injection port is open to the first compression chamber or the second compression chamber.