An internal combustion piston comprises a modified layer produced by a surface treatment including injecting injection powders having a diameter of 20 \u03bcm to 400 \u03bcm and containing a reinforcing element to be collided with a surface of the internal combustion piston obtained by casting and forging by injecting at an injection speed of 80 ms or more or at an injection pressure of 0. A first composition of dopants included in the first part of continuous glass structure differs from a second composition of dopants of the second part of the continuous glass structure. Treatment means for particulate matter 3 comprises different vibrating bodies 2 and 4 linking with vibrating means 1 being grouped together, and is configured in such a manner as to subject the particulate matter 3 to fluidization treatment due to the cooperative oscillating action caused between the different oscillators.