Conductive powder, conductive material containing the same, and method for producing the same

A method of producing a conductive powder, comprising:

• a process A of mixing an electroless plating solution containing nickel ions and a hypophosphorate salt with core particles carrying a noble metal to prepare a slurry containing the core particles with an initial nickel thin film formed on their surfaces, wherein a concentration of the nickel ions is adjusted to 0.0085 to 0.34 mole/L, an amount of the hypophosphorate salt is adjusted such that its molar ratio to an amount of the nickel ions ranges from 0.01 to 0.5, and the core particles are used in an amount such that a total area thereof based on one liter of the electroless plating solution ranges from 1 m2 to 15 m2;
• and
• a process B of simultaneously and continuously adding the nickel ions, the hypophosphorate salt and a basic material to the slurry prepared in the process A, so that the nickel ions are reduced to form nickel fine-particles in the slurry, and a plurality of protrusions, each of which comprises a particle chain comprising a plurality of the nickel fine-particles linked in a row, is formed on a surface of the initial nickel film on the core particles.