To provide a laminated balun transformer, wherein a favorable coupling can be obtained in a wide band extending to a high frequency than a GHz.

A laminated balun transformer is constituted in a structure that non-magnetic material layers 2a and 2b having a polyvinyl benzyl ether compound are respectively made to interpose between strip lines 4 and 5 and 6 and 7, which are subjected to electromagnetic coupling and form a pair. Magnetic material layers 1a and 1b and 1c and 1d formed by making magnetic powder scatter in a polyvinyl benzyl ether compound are respectively provided on the upper and lower sides of composite layers, which respectively consist of the strip lines 4 and 5 forming the pair and the layer 2a and the strip lines 6 and 7 having the pair and the layer 2b. In this structure, as the compound is low in a specific permittivity, a capacity coupling between the strip lines 4 and 5 and 6 and 7 is small and a magnetic flux interlinkage between the strip lines is augmented and the high-frequency characteristics of the laminated balun transformer are improved.