An interleaved converter (50, 51, 52) including n first switching converter circuits (501 to 504) (n is an integer equal to or larger than 2) connected in parallel, a rectifier circuit that rectifies an alternating-current voltage output from an alternating-current power supply, wherein each said first switching converter circuit is configured to include an inductor (5a to 5d), a switching element (6a to 6d) and a diode (7a to 7d), wherein the inductor (5a to 5d) comprises a first end and a second end and the interleaved converter (50, 51, 52) is further configured to switch, with the switching elements, an output voltage of the rectifier circuit via the inductors to perform one or both of power factor improvement and a boosting operation and to supply electric power to a load, the interleaved converter being characterized by: an inter-inductor switch (103a to 103c) that is connected between the first end of the inductor of one stage and the second end of the inductor of the next stage and makes it possible to select whether the inductors are connected in series by connecting or disconnecting the first end of the inductor of one stage with the second end of the inductor of the next stage; an input side switch (101a to 101c) that is connected between the output end of the rectifier circuit and the connection point of the first end of the inductor (5a to 5c) of the one stage and one end of the inter-inductor switch (103a to 103c) and makes it possible to select whether electric power is supplied from the rectifier circuit to the inductor side; an output side switch (102a to 102c) that is connected between the anode of the diode (7b to 7d) and the connection point of the second end of the inductor (5b to 5d) of the next stage and the other end of the inter-inductor switch (103a to 103c) and makes it possible to select whether electric power is supplied from the inductor to the diode side; and a control circuit (4, 4a, 4b) that is configured to control the inter-inductor switch, the input side switch, and the output side switch. an inter-inductor switch (103a to 103c) that is connected between the first end of the inductor of one stage and the second end of the inductor of the next stage and makes it possible to select whether the inductors are connected in series by connecting or disconnecting the first end of the inductor of one stage with the second end of the inductor of the next stage; an input side switch (101a to 101c) that is connected between the output end of the rectifier circuit and the connection point of the first end of the inductor (5a to 5c) of the one stage and one end of the inter-inductor switch (103a to 103c) and makes it possible to select whether electric power is supplied from the rectifier circuit to the inductor side; an output side switch (102a to 102c) that is connected between the anode of the diode (7b to 7d) and the connection point of the second end of the inductor (5b to 5d) of the next stage and the other end of the inter-inductor switch (103a to 103c) and makes it possible to select whether electric power is supplied from the inductor to the diode side; and a control circuit (4, 4a, 4b) that is configured to control the inter-inductor switch, the input side switch, and the output side switch.