To provide a tab terminal capable of connecting a flat wiring member certainly, its flat wiring member connecting structure, and an electric connection box.

The tab terminal 5 has a stairs shape of one step bent at two places in reverse directions. A vertical face at upper part of the stairs shape is made a first face 5a, a horizontal face following it is made a second face 5b, and the vertical face at further lower part is made a third face 5c. The upper end portion of the first face 5a is chamfered so that the member may be narrower toward the upper part, and the third face 5c becomes smaller in width and thinner in thickness as it goes toward the lower part. The flat wiring member 3 has a conductive member 3a covered by an insulating member 3b, and has a land 4 formed in which the upper side of the insulating member 3b is peeled off and the conductive member 3a is exposed at a prescribed location. The bottom face of the second face 5b is jointed electrically to the exposed conductive member 3b at this land 4. Further, the third face 5c is engaged with a hole 1a (2a) facing the wiring face 1S (2S) and fastens the flat wiring member to an insulating panel 1 (2).