A tape cassette wherein, on one of the central upper portion of a reel and a pressure mechanism, there is disposed a center pin, on the other, there is formed a contacting flat plate portion with which the center pin can be contacted, one of the center pin and contacting flat plate portion is molded mainly of polyacetal-system synthetic resin, the other is molded mainly of polybutylene-system or polyethylene-system synthetic resin, and inorganic powder is added to at least one of these two kinds of synthetic resin.