The flexible printed wiring board according to the present invention includes a first flexible insulating layer, a first conductor wiring laminated on the first insulating layer, a second single-layered insulating layer laminated on the first insulating layer, as it covers the first conductor wiring, and a second conductor wiring laminated on the second insulating layer. The first conductor wiring has a thickness in the range of 10 to 30 μm, a line width in the range of 50 μm to 1 mm, and a line gap in the range of 50 μm to 1 mm. The thickness from the surface of the first conductor wiring to the surface of the second insulating layer is in the range of 5 to 30 μm. The surface waviness of the part of the second insulating layer covering the first conductor wiring is 10 μm or less.