To provide an efficient hybridization apparatus of a simple structure capable of shortening reaction time of a selectively bonding substance.

On a substrate, the selective bonding substance is arranged in a region for arranging the selective bonding substance. A sample solution to be tested, which contains a corresponding selective bonding substance which selectively bonds to the selective bonding substance, is brought into action to hybridize the selective bonding substance and the corresponding selective bonding substance in a process. The method for hybridizing the selective bonding substance comprises a process for impressing an A.D. voltage between conductive electrodes arranged outside both ends of the region for arranging the selective bonding substance in a direction which intersects a vertical axis of a plane for arranging the selective bonding substance in the hybridization process.