Provided is a balance-unbalance converter including: a substrate; an unbalanced line; a first balanced line; and a second balanced line on the substrate. The unbalanced line has a first end at which an unbalanced signal is input, and an opened second end. The first balanced line is in parallel with a line portion of the unbalanced line from the first end to a midpoint of the unbalanced line, and has a midpoint-side third end at which a balanced signal is output, and a grounded fourth end. The second balanced line is in parallel with a line portion of the unbalanced line from the second end to the midpoint, and has a midpoint-side fifth end at which the balanced signal is output, and a grounded sixth end. The unbalanced line is bent at the midpoint toward an opposite side of the first and second balanced lines.