The porous carbon material utilizing the natural porous structure of rice bran has been produced and used as a linear motion slider. The rice-bran carbon-materials is produced mixing with a phenol resin and then carbonized under nitrogen gas atmosphere. Therefore, the components such as Mg, P, K in the rice bran are included in the rice-bran carbon-materials. Moreover, Na in phenol resin is also included in the rice-bran carbon-materials. These components may make a chemical compound with absorbency during the carbonizing. In this study, some improving methods to increase the mater resistance were discussed eliminating the absorbency compound and using phenol resin without Na.