There are provided an electrically conductive adhesive agent capable of providing good electrical continuity to a substrate to which a preflux treatment has been applied, and a method for connecting electronic components. The electrically conductive adhesive agent to be used includes a polymerizable acrylic compound, an organic peroxide, and the solder particles, the organic peroxide having a one minute half-life temperature lower than the solidus temperature of the solder particles. At the time of thermocompression bonding, the solder particles are crushed and an oxide film is removed, and a preflux layer on the surface of a bump is also removed by melting and flowing thereof, whereby electrical continuity is secured, and then an adhesive component is completely cured.